ci: cap component-tests jobs at 30 minutes (#973)

A stuck post-step (e.g. actions/setup-go's cache-save) can otherwise
run for the full 6-hour hosted-runner ceiling, and GitHub never
flushes a force-cancelled job's log tail -- turning an unrelated
infra stall into an undiagnosable multi-hour mystery. go test's own
--timeout=20m already bounds real test hangs; this just bounds
everything else around it too.


Claude-Session: https://claude.ai/code/session_01LCMGT6Po2tSr1VEDVrbbYd

Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>