Validate took ~10 minutes, of which ~10 seconds was work: setup-go's
cache restore and save each waited ~4.7 minutes for a connect timeout,
because the runners' built-in cache server sits on a network job
containers can't reach. Turn off setup-go caching (three small modules
aren't worth it) and the game-test runner's cache server, so any cache
step skips at once.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>