how to fix npm ERR! code ELIFECYCLE (heroku)

I'm currently working on a project since i've been teaching myself Angular over the past couple weeks. I wrote up my code, created what I thought I needed for deploying on heroku and tried to deploy it. I received the following error

-----> Build
   Detected both "build" and "heroku-postbuild" scripts
   Running heroku-postbuild
   
   > purposefularmament@0.0.0 heroku-postbuild /tmp/build_2c8456a0
   > ng build --configuration production
   npm ERR! code ELIFECYCLE
   npm ERR! errno 3
   npm ERR! purposefularmament@0.0.0 heroku-postbuild: `ng build --configuration 
   production`
   npm ERR! Exit status 3
   npm ERR! 
   npm ERR! Failed at the purposefularmament@0.0.0 heroku-postbuild 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!     /tmp/npmcache.JjS0Q/_logs/2022-09-23T14_54_55_966Z-debug.log
   -----> Build failed

after doing some research I only found that this error is caused by an issue with my npm install. I deleted my node_modules file and removed package-lock.json, cleared the npm cache and then reinstalled npm. I repushed the code and Im still getting this same error.

Any suggestions?

Here is my package.json and server.js files

{
"name": "purposefularmament",
"version": "0.0.0",
 "scripts": {
  "ng": "ng",
  "start": "node server.js",
  "build": "ng build",
  "test": "ng test",
  "lint": "ng lint",
  "e2e": "ng e2e",
  "heroku-postbuild": "ng build --configuration production"
},
 "private": true,
   "dependencies": {
     "@angular/animations": "~11.1.2",
     "@angular/cli": "^14.2.3",
     "@angular/common": "~11.1.2",
     "@angular/compiler": "~11.1.2",
     "@angular/compiler-cli": "^11.2.14",
     "@angular/core": "~11.1.2",
     "@angular/forms": "~11.1.2",
     "@angular/platform-browser": "~11.1.2",
     "@angular/platform-browser-dynamic": "~11.1.2",
     "@angular/router": "~11.1.2",
     "bootstrap": "^5.2.1",
     "bootstrap-icons": "^1.9.1",
     "bulma": "^0.9.4",
     "express": "^4.18.1",
     "grunt-express": "^1.4.1",
     "node": "^14.15.0",
     "path": "^0.12.7",
     "rxjs": "~6.6.0",
     "tslib": "^2.0.0",
     "typescript": "~4.1.2",
     "zone.js": "~0.11.3"
 },
  "devDependencies": {
    "@angular-devkit/build-angular": "~0.1101.4",
    "@angular/cli": "^14.2.3",
    "@angular/compiler-cli": "^11.2.14",
    "@types/jasmine": "~3.6.0",
    "@types/node": "^12.11.1",
    "autoprefixer": "^10.4.8",
    "codelyzer": "^6.0.0",
    "jasmine-core": "~3.6.0",
    "jasmine-spec-reporter": "~5.0.0",
    "karma": "~5.2.0",
    "karma-chrome-launcher": "~3.1.0",
    "karma-coverage": "~2.0.3",
    "karma-jasmine": "~4.0.0",
    "karma-jasmine-html-reporter": "^1.5.0",
    "postcss": "^8.4.16",
    "protractor": "~7.0.0",
    "tailwindcss": "^3.1.8",
    "ts-node": "~8.3.0",
    "tslint": "~6.1.0",
    "typescript": "~4.1.2"
 },
  "engines": {
    "node": "14.15.0",
    "npm": "6.14.13"
 }
}

and server.js

    //Install express server
    const express = require('express');
    const path = require('path');

    const app = express();

    // Serve only the static files form the dist directory
    app.use(express.static(__dirname + '/dist/purposefularmament'));

    app.get('/*', function(req,res) {
       res.sendFile('index.html', {root: 'dist/purposefularmament/'});
    });
    
    // Start the app by listening on the default Heroku port
    app.listen(process.env.PORT || 8080);