webpackでwebpack-dev-serverを設定し、npm run startの際のエラーについて

webpackで環境構築の練習をしていまして、その中でwebpack-dev-serverを設定する際、ビルド(npm run start)すると原因不明のエラーが出ており
解決できずに手が止まっています。
原因わかる方、少しでも検討つく方いらっしゃいましたら、ご回答頂けますと幸いです。
よろしくお願いいたします。

エラー文

> getting-started-webpack@1.0.0 start /Users/hayashiyuugo/Documents/学習/getting-started-webpack
> webpack-dev-server

[webpack-cli] /Users/hayashiyuugo/Documents/学習/getting-started-webpack/node_modules/webpack-dev-server/lib/servers/WebsocketServer.js:10
  static heartbeatInterval = 1000;
                           ^

SyntaxError: Unexpected token =
    at new Script (vm.js:79:7)
    at createScript (vm.js:251:10)
    at Object.runInThisContext (vm.js:303:10)
    at Module._compile (internal/modules/cjs/loader.js:656:28)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:699:10)
    at Module.load (internal/modules/cjs/loader.js:598:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:537:12)
    at Function.Module._load (internal/modules/cjs/loader.js:529:3)
    at Module.require (internal/modules/cjs/loader.js:636:17)
    at require (internal/modules/cjs/helpers.js:20:18)
npm ERR! code ELIFECYCLE
npm ERR! errno 2
npm ERR! getting-started-webpack@1.0.0 start: `webpack-dev-server`
npm ERR! Exit status 2
npm ERR! 
npm ERR! Failed at the getting-started-webpack@1.0.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/hayashiyuugo/.npm/_logs/2022-11-18T12_12_57_048Z-debug.log

webpack.config.js

const path = require("path");
const MiniCssExtractPlugin = require("mini-css-extract-plugin");

module.exports = {
    //mode
    mode : 'development', //development:ソースマップを生成し、再ビルド時間が短縮される //production: モジュールの圧縮、最適化される
    //entrypoint
    entry : './src/js/app.js',
    //出力の設定
    output : {
        //出力先のpath
        path : path.resolve(__dirname, 'public'),
        //出力するファイル名
        filename : 'js/bundle.js',
        clean : true
    },
    devServer: {
        open : true,
        port : 9000,
        static : {
            directory: path.join(__dirname, "public")
        }
    },
    module: {
        rules : [
            {
                test : /\.scss$/,
                include : path.resolve(__dirname, 'src/scss'),
                use : [
                    'style-loader',
                    MiniCssExtractPlugin.loader,
                    'css-loader',
                    'postcss-loader',
                    'sass-loader'
                ],
            },
        ],
    },
    plugins : [
        new MiniCssExtractPlugin({
            filename: './css/style.css',
        })
    ]
}

package.json

{
  "name": "getting-started-webpack",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "webpack-dev-server",
    "build": "webpack"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "autoprefixer": "^10.2.5",
    "css-loader": "^5.2.0",
    "mini-css-extract-plugin": "^2.7.0",
    "postcss": "^8.2.8",
    "postcss-loader": "^5.2.0",
    "sass": "^1.32.8",
    "sass-loader": "^11.0.1",
    "style-loader": "^2.0.0",
    "webpack": "^5.30.0",
    "webpack-cli": "^5.0.0",
    "webpack-dev-server": "^4.11.1"
  },
  "dependencies": {
    "jquery": "^3.6.0"
  }
}