Added Patch to route

[Flo-Mueller]

This PR solves #486 and simply adds Patch to the route, so that it is consistent to the other annotations like @Route.get or @Route.post.

---

• I’ve reviewed the contributor guide and applied the relevant portions to this PR.

Contribution guidelines:

• See our contributor guide for general expectations for PRs.
• Larger or significant changes should be discussed in an issue before creating a PR.
• Contributions to our repos should follow the Dart style guide and use dart format.
• Most changes should add an entry to the changelog and may need to rev the pubspec package version.
• Changes to packages require corresponding tests.

Many Dart repos have a weekly cadence for reviewing PRs - please allow for some latency before initial review feedback.

Note: The Dart team is trialing Gemini Code Assist. Don't take its comments as final Dart team feedback. Use the suggestions if they're helpful; otherwise, wait for a human reviewer.

[brianquinlan]

Please add a note to CHANGELOG.md and update the minor version to 1.5.0-wip and change pubspec.yaml to match it.

Also, should you also update pkgs/shelf_router_generator/test/server/unrelatedannotation.dart ?