An external JavaScript runtime (e.g. QuickJS) is now required for full
YouTube support.
Add QuickJS as a dependency and use it as an external runtime.
Move cache to /var/cache.
Changelog: https://github.com/yt-dlp/yt-dlp/releases/tag/2025.11.12
Signed-off-by: George Sapkin <george@sapk.in>