Simplify fileURLToPath usage in scripts

What does this MR do and why?

Allow import extensions in scripts

Rather than repeatedly disabling it, just allow it in scripts and configuration files.

Fix find_frontend_files script

This was broken !170174 (merged).

Node requires file extensions when used with the import statement.

Simplify fileURLToPath usage in scripts

The dirname and filename properties of import.meta were added in Node 20.11.0, and we've been on 20.12.2 for a while.

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

n/a

How to set up and validate locally

These scripts should all operate normally without any errors. You don't need to know what these scripts do or how they work, only that they don't error out.

• config/helpers/vite_plugin_style.mjs
  • Run the GDK locally with Vite enabled. There should be no obvious errors.
• scripts/frontend/lib/compile_css.mjs
  • As above.
• scripts/frontend/tailwindcss.mjs
  • As above, and also:
  • node scripts/frontend/tailwindcss.mjs
• eslint.config.mjs
  • Run yarn lint:eslint jest_resolver.js, or similar.
• scripts/frontend/find_frontend_files.mjs
  • scripts/frontend/find_frontend_files.mjs app/assets/javascripts/awards_handler.js.
  • This was broken by !170174 (merged), but now should work.
• scripts/frontend/preinstall.mjs
  • yarn install