events.js:292 throw er; // Unhandled 'error' eventのエラー解決法について

前提・実現したいこと　

HerokuにPushしたLaravelアプリに Vue を反映させるため、Herokuのbash内でnpm run devを実行したいのですが、以下のエラーが生じてしまい、上手く Vue が聞いてくれません。
もし何か思いつく方がいらっしゃれば教えて頂きたいです。

発生している問題

> dev
> npm run development


> development
> cross-env NODE_ENV=development node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js

events.js:292
      throw er; // Unhandled 'error' event
      ^

Error: spawn node_modules/webpack/bin/webpack.js ENOENT
    at Process.ChildProcess._handle.onexit (internal/child_process.js:269:19)
    at onErrorNT (internal/child_process.js:465:16)
    at processTicksAndRejections (internal/process/task_queues.js:80:21)
Emitted 'error' event on ChildProcess instance at:
    at Process.ChildProcess._handle.onexit (internal/child_process.js:275:12)
    at onErrorNT (internal/child_process.js:465:16)
    at processTicksAndRejections (internal/process/task_queues.js:80:21) {
  errno: -2,
  code: 'ENOENT',
  syscall: 'spawn node_modules/webpack/bin/webpack.js',
  path: 'node_modules/webpack/bin/webpack.js',
  spawnargs: [
    '--progress',
    '--hide-modules',
    '--config=node_modules/laravel-mix/setup/webpack.config.js'
  ]
}

該当のソースコード

packagejson
1{
2    "private": true,
3    "scripts": {
4        "heroku-postbuild": "npm run prod",
5        "dev": "npm run development",
6        "development": "mix",
7        "watch": "mix watch",
8        "watch-poll": "mix watch -- --watch-options-poll=1000",
9        "hot": "mix watch --hot",
10        "prod": "npm run production",
11        "production": "mix --production"
12    },
13    "devDependencies": {
14        "@johmun/vue-tags-input": "^2.1.0",
15        "axios": "^0.19",
16        "cross-env": "^5.1",
17        "laravel-mix": "^4.0.7",
18        "lodash": "^4.17.13",
19        "resolve-url-loader": "^2.3.1",
20        "sass": "^1.15.2",
21        "sass-loader": "^7.1.0",
22        "vue": "^2.6.11",
23        "vue-template-compiler": "^2.6.11"
24    }
25}

webpackmixjs
1const mix = require('laravel-mix');
2
3/*
4 |--------------------------------------------------------------------------
5 | Mix Asset Management
6 |--------------------------------------------------------------------------
7 |
8 | Mix provides a clean, fluent API for defining some Webpack build steps
9 | for your Laravel application. By default, we are compiling the Sass
10 | file for the application as well as bundling up all the JS files.
11 |
12 */
13
14mix.js('resources/js/app.js', 'public/js')
15  .sass('resources/sass/app.scss', 'public/css')
16  .version();
17