Chore: Remove unnecessary packages

Because:
- I think we needed these at one point for Webpack to compile correctly.
- We shouldn't need to load them in directly, any packages that depend on them, will have them as their dependency.

This commit:
- Removes core-js package
- Removes regenerator-runtime package

app/javascript/main.js

@@ -1,5 +1,3 @@
-import 'core-js/stable';
-import 'regenerator-runtime/runtime';
 import './controllers';
 import '@hotwired/turbo-rails';
 import './src/custom_turbo_stream_actions';

package.json

@@ -21,7 +21,6 @@
     "chartjs-plugin-crosshair": "^2.0.0",
     "chartjs-plugin-tailwindcss-colors": "^0.2.2",
     "chokidar": "^3.6.0",
-    "core-js": "^3.37.0",
     "debounce": "^1.2.1",
     "el-transition": "^0.0.7",
     "esbuild": "^0.23.0",
@@ -32,7 +31,6 @@
     "postcss": "^8.4.40",
     "postcss-import": "^16.1.0",
     "prismjs": "^1.29.0",
-    "regenerator-runtime": "^0.14.1",
     "sortablejs": "^1.15.0",
     "stimulus-use": "^0.51.3",
     "tailwindcss": "^3.4.1",