fastify 5.12.0 on Node.js NPM

What's Changed

chore(sponsor): add testmu ai by @Eomm in #6922
docs: add per-route logging for Google Cloud Functions by @slegarraga in #6907
test: remove @sinonjs/fake-timers by @climba03003 in #6934
[Backport 5.x] fix: remove raw response headers by @github-actions[bot] in #6939
[Backport 5.x] test: use process-warning spyWarning for testing by @github-actions[bot] in #6945
[Backport 5.x] feat: add Reply.prototype.mediaType by @github-actions[bot] in #6946
[Backport 5.x] fix(content-type): return undefined for invalid media types by @github-actions[bot] in #6947

Full Changelog: v5.11.3...v5.12.0