Bump peter-evans/create-pull-request from 3 to 6

Bumps [peter-evans/create-pull-request](https://github.com/peter-evans/create-pull-request) from 3 to 6.
- [Release notes](https://github.com/peter-evans/create-pull-request/releases)
- [Commits](peter-evans/create-pull-request@v3...v6)

---
updated-dependencies:
- dependency-name: peter-evans/create-pull-request
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/alerting-swagger-gen.yml

@@ -21,7 +21,7 @@ jobs:
         run: |
           make -C pkg/services/ngalert/api/tooling post.json api.json
       - name: Open Pull Request
-        uses: peter-evans/create-pull-request@v5
+        uses: peter-evans/create-pull-request@v6
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           commit-message: "chore: update alerting swagger spec"