git push heroku master できない

前提

railsチュートリアルを進めています
cloud9で git push heroku master　コマンドを実行しようとするとエラーになってしまいます。

実現したいこと

git push heroku master を実行する

発生している問題・エラーメッセージ

$ git push heroku master
Counting objects: 107, done.
Compressing objects: 100% (89/89), done.
Writing objects: 100% (107/107), 53.10 KiB | 1.90 MiB/s, done.
Total 107 (delta 7), reused 0 (delta 0)
remote: Compressing source files... done.
remote: Building source:
remote: 
remote: -----> Building on the Heroku-22 stack
remote: -----> Determining which buildpack to use for this app
remote:  !     Warning: Multiple default buildpacks reported the ability to handle this app. The first buildpack in the list below will be used.
remote:                         Detected buildpacks: Ruby,Node.js
remote:                         See https://devcenter.heroku.com/articles/buildpacks#buildpack-detect-order
remote: -----> Ruby app detected
remote: -----> Installing bundler 1.17.3
remote: -----> Removing BUNDLED WITH version in the Gemfile.lock
remote: -----> Compiling Ruby/Rails
remote: -----> Using Ruby version: ruby-3.1.2
remote: -----> Installing dependencies using bundler 1.17.3
remote:        Running: BUNDLE_WITHOUT='development:test' BUNDLE_PATH=vendor/bundle BUNDLE_BIN=vendor/bundle/bin BUNDLE_DEPLOYMENT=1 BUNDLE_GLOBAL_PATH_APPENDS_RUBY_SCOPE=1 bundle install -j4
remote:        Fetching gem metadata from https://rubygems.org/..........
remote:        Fetching rake 12.3.3
remote:        Installing rake 12.3.3
remote:        Fetching concurrent-ruby 1.1.10
remote:        Fetching minitest 5.16.3
remote:        Fetching zeitwerk 2.6.0
remote:        Fetching thread_safe 0.3.6
remote:        Installing minitest 5.16.3
remote:        Installing zeitwerk 2.6.0
remote:        Installing concurrent-ruby 1.1.10


※字数制限の為省略



remote:        Fetching sass-listen 4.0.0
remote:        Installing sass-listen 4.0.0
remote:        Fetching sass 3.7.4
remote:        Installing sass 3.7.4
remote:        Fetching sass-rails 5.1.0
remote:        Installing sass-rails 5.1.0
remote:        Installing actionmailer 6.0.4
remote:        Fetching rails 6.0.4
remote:        Installing rails 6.0.4
remote:        Bundle complete! 18 Gemfile dependencies, 59 gems now installed.
remote:        Gems in the groups 'development' and 'test' were not installed.
remote:        Bundled gems are installed into `./vendor/bundle`
remote:        Post-install message from sass:
remote:        
remote:        Ruby Sass has reached end-of-life and should no longer be used.
remote:        
remote:        * If you use Sass as a command-line tool, we recommend using Dart Sass, the new
remote:          primary implementation: https://sass-lang.com/install
remote:        
remote:        * If you use Sass as a plug-in for a Ruby web framework, we recommend using the
remote:          sassc gem: https://github.com/sass/sassc-ruby#readme
remote:        
remote:        * For more details, please refer to the Sass blog:
remote:          https://sass-lang.com/blog/posts/7828841
remote:        
remote:        Bundle completed (81.79s)
remote:        Cleaning up the bundler cache.
remote: -----> Installing node-v16.13.1-linux-x64
remote: -----> Installing yarn-v1.22.17
remote: -----> Detecting rake tasks
remote: -----> Preparing app for Rails asset pipeline
remote:        Running: rake assets:precompile
remote:        Rails couldn't infer whether you are using multiple databases from your database.yml and can't generate the tasks for the non-primary databases. If you'd like to use this feature, please simplify your ERB.
remote:        rake aborted!
remote:        Psych::BadAlias: Unknown alias: default
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/webpacker-4.0.7/lib/webpacker/env.rb:30:in `available_environments'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/webpacker-4.0.7/lib/webpacker/env.rb:21:in `current'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/webpacker-4.0.7/lib/webpacker/env.rb:15:in `inquire'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/webpacker-4.0.7/lib/webpacker/env.rb:7:in `inquire'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/webpacker-4.0.7/lib/webpacker/instance.rb:11:in `env'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/webpacker-4.0.7/lib/webpacker/instance.rb:18:in `config'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/webpacker-4.0.7/lib/webpacker.rb:26:in `config'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/webpacker-4.0.7/lib/webpacker/railtie.rb:32:in `block in <class:Engine>'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/railties-6.0.4/lib/rails/initializable.rb:32:in `instance_exec'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/railties-6.0.4/lib/rails/initializable.rb:32:in `run'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/railties-6.0.4/lib/rails/initializable.rb:61:in `block in run_initializers'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/railties-6.0.4/lib/rails/initializable.rb:60:in `run_initializers'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/railties-6.0.4/lib/rails/application.rb:363:in `initialize!'
remote:        /tmp/build_0082593b/config/environment.rb:5:in `<main>'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.10.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:30:in `require'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.10.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:30:in `require'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/zeitwerk-2.6.0/lib/zeitwerk/kernel.rb:35:in `require'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/activesupport-6.0.4/lib/active_support/dependencies.rb:324:in `block in require'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/activesupport-6.0.4/lib/active_support/dependencies.rb:291:in `load_dependency'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/activesupport-6.0.4/lib/active_support/dependencies.rb:324:in `require'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/railties-6.0.4/lib/rails/application.rb:339:in `require_environment!'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/railties-6.0.4/lib/rails/application.rb:523:in `block in run_tasks_blocks'
remote:        /tmp/build_0082593b/vendor/bundle/ruby/3.1.0/gems/sprockets-rails-3.4.2/lib/sprockets/rails/task.rb:61:in `block (2 levels) in define'
remote:        Tasks: TOP => environment
remote:        (See full trace by running task with --trace)
remote: 
remote:  !
remote:  !     Precompiling assets failed.
remote:  !
remote:  !     Push rejected, failed to compile Ruby app.
remote: 
remote:  !     Push failed
remote:  !
remote:  ! ## Warning - The same version of this code has already been built: 127e0ffd899e2547ffe347533363be32a506951b
remote:  !
remote:  ! We have detected that you have triggered a build from source code with version 127e0ffd899e2547ffe347533363be32a506951b
remote:  ! at least twice. One common cause of this behavior is attempting to deploy code from a different branch.
remote:  !
remote:  ! If you are developing on a branch and deploying via git you must run:
remote:  !
remote:  !     git push heroku <branchname>:main
remote:  !
remote:  ! This article goes into details on the behavior:
remote:  !   https://devcenter.heroku.com/articles/duplicate-build-version
remote: 
remote: Verifying deploy....
remote: 
remote: !       Push rejected to fathomless-shore-68344.
remote: 
To https://git.heroku.com/fathomless-shore-68344.git
 ! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'https://git.heroku.com/fathomless-shore-68344.git'

該当のソースコード

ソースコード

試したこと

psych::badalias: unknown alias: default　のエラーが原因だと思ったので検索し、以下のアプローチを試しました。
①gemfileに　gem 'psych', '~> 3.1'　を追加　→ 　bundle install コマンド実行
②rails 6.1.4以降　で解決できるとのことなのでgemfileのrailsを　rails 6.1.4　に変更