ci: raise the test job limit from 15 to 25 minutes

[llima]

Summary

• The test job's timeout-minutes goes from 15 to 25. The Windows jobs ran 12m29s to 14m56s against the 15 minute limit, and one run that had passed every step was cancelled at 15m0s.
• One key bounds every job of the matrix, so the Linux jobs get the same limit.
• No version change: merging this publishes nothing. release.yml, the vitest timeouts and every test other than the pinned assertion are untouched.

Test plan

• test/ci.test.ts › bounds the job so a hang doesn't burn the runner — not run by hand (it is never part of a by-hand run); this PR's CI is its run
• npm run typecheck, npm run build, npm test — not run locally: no file under src/ is in the range; this PR's CI runs them
• oracle: skipped (no fixture); no emitted byte is touched
• the four matrix jobs finish, Windows included