Remove LESS stylesheets and dependencies (#27409)

* Remove components, core and modules LESS stylesheets

* Remove variables LESS stylesheets

* Remove app LESS stylesheets

* Remove github-sync, onboarding LESS stylesheets

* Remove main-light and IEEE LESS stylesheets

* Remove Less loader configuration

* Remove bootstrap-3 entrypoint

* Rename bootstrap-5 entrypoint to bootstrap

* Remove bootstrap-5 CSS folder and move stylesheets

* Update CSS variables

* Restore and update github-sync.scss path

* Fix try-premium.scss path and fix undefined mixin error

* Restore entrypoints

* Simplify buildCssPath to always use main-style.css

* Remove less from prettier formatting scripts

* Remove less from addHook extension

* Source format

* Remove nvd3 file reference from prettierignore (equivalent of nvd3.scss)

* Remove less and less-loader

* Add SCSS files to pirates require hook

GitOrigin-RevId: bd83c79f4d6ef7305d75993959a4dc5e7714ef9c

services/web/test/frontend/bootstrap.js

@@ -92,7 +92,7 @@ globalThis.fetch =
 // ignore style/image files
 const { addHook } = require('pirates')
 addHook(() => '', {
-  exts: ['.css', '.less', '.svg', '.png', '.gif', '.mp4'],
+  exts: ['.css', '.scss', '.svg', '.png', '.gif', '.mp4'],
   ignoreNodeModules: false,
 })