Herokuのデプロイができない

LaravelのアプリをHerokuでデプロイするのに、下記の手順に従い作業していたのですが、
git push heroku masterのコマンドを打つとエラーが出て正しくデプロイができません。
https://www.hypertextcandy.com/laravel-tutorial-deploy-to-heroku#heroku-%E3%81%A8%E3%81%AF

実際にアプリを開いてみるとこうなります。

git push heroku masterを入力したときのエラー文

remote:        > @php artisan package:discover --ansi
remote:        
remote:        In Auth.php line 56:
remote:                                                                                       
remote:          In order to use the Auth::routes() method, please install the laravel/ui pa  
remote:          ckage.                                                                       
remote:                                                                                       
remote:        
remote:        Script @php artisan package:discover --ansi handling the post-autoload-dump event returned with error code 1
remote:  !     WARNING: A post-autoload-dump script terminated with an error
remote: 
remote:  !     ERROR: Dependency installation failed!
remote:  !     
remote:  !     The 'composer install' process failed with an error. The cause
remote:  !     may be the download or installation of packages, or a pre- or
remote:  !     post-install hook (e.g. a 'post-install-cmd' item in 'scripts')
remote:  !     in your 'composer.json'.
remote:  !     
remote:  !     Typical error cases are out-of-date or missing parts of code,
remote:  !     timeouts when making external connections, or memory limits.
remote:  !     
remote:  !     Check the above error output closely to determine the cause of
remote:  !     the problem, ensure the code you're pushing is functioning
remote:  !     properly, and that all local changes are committed correctly.
remote:  !     
remote:  !     For more information on builds for PHP on Heroku, refer to
remote:  !     https://devcenter.heroku.com/articles/php-support
remote:  !     
remote:  !     REMINDER: the following warnings were emitted during the build;
remote:  !     check the details above, as they may be related to this error:
remote:  !     - A post-autoload-dump script terminated with an error
remote: 
remote:  !     Push rejected, failed to compile PHP app.
remote: 
remote:  !     Push failed
remote: !
remote:  ! ## Warning - The same version of this code has already been built: d71eba1e23ad38860e5339e164d65652be1f6cac
remote:  !
remote:  ! We have detected that you have triggered a build from source code with version d71eba1e23ad38860e5339e164d65652be1f6cac
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 microposterapp.
remote: 
To https://git.heroku.com/microposterapp.git
 ! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'https://git.heroku.com/microposterapp.git'

###　やったこと h3

composer.jsonのconfigに
**"bin-dir": "vender/bin"**を追記した。

{
    "name": "laravel/laravel",
    "type": "project",
    "description": "The Laravel Framework.",
    "keywords": [
        "framework",
        "laravel"
    ],
    "license": "MIT",
    "require": {
        "php": "^7.2.5",
        "barryvdh/laravel-debugbar": "^3.5",
        "doctrine/dbal": "^2.11",
        "fideloper/proxy": "^4.2",
        "fruitcake/laravel-cors": "^2.0",
        "guzzlehttp/guzzle": "^6.3",
        "intervention/image": "^2.5",
        "laravel/framework": "^7.24",
        "laravel/tinker": "^2.0",
        "laravelcollective/html": "^6.2"
    },
    "require-dev": {
        "facade/ignition": "^2.0",
        "fzaninotto/faker": "^1.9.1",
        "laravel/ui": "^2.0",
        "mockery/mockery": "^1.3.1",
        "nunomaduro/collision": "^4.1",
        "phpunit/phpunit": "^8.5"
    },
    "config": {
        "optimize-autoloader": true,
        "preferred-install": "dist",
        "sort-packages": true,
        "bin-dir": "vender/bin"
    },
    "extra": {
        "laravel": {
            "dont-discover": []
        }
    },
    "autoload": {
        "psr-4": {
            "App\": "app/"
        },
        "classmap": [
            "database/seeds",
            "database/factories"
        ]
    },
    "autoload-dev": {
        "psr-4": {
            "Tests\": "tests/"
        }
    },
    "minimum-stability": "dev",
    "prefer-stable": true,
    "scripts": {
        "post-autoload-dump": [
            "Illuminate\Foundation\ComposerScripts::postAutoloadDump",
            "@php artisan package:discover --ansi"
        ],
        "post-root-package-install": [
            "@php -r \"file_exists('.env') || copy('.env.example', '.env');\""
        ],
        "post-create-project-cmd": [
            "@php artisan key:generate --ansi"
        ]
    }
}

エラー文を調べてもよくわからなかったので、ヒントをいただけると幸いです。
どうかよろしくお願いいたします。