Bump peter-evans/create-pull-request from 5 to 6

Bumps [peter-evans/create-pull-request](https://github.com/peter-evans/create-pull-request) from 5 to 6.
- [Release notes](https://github.com/peter-evans/create-pull-request/releases)
- [Commits](peter-evans/create-pull-request@v5...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/ci.yml

@@ -107,7 +107,7 @@ jobs:
       - id: diff
         run: tools/ci/gen.sh
         if: github.repository_owner == 'taiki-e' && (github.event_name == 'schedule' || github.event_name == 'push' && github.ref == 'refs/heads/main')
-      - uses: peter-evans/create-pull-request@v5
+      - uses: peter-evans/create-pull-request@v6
         with:
           title: Update generated code
           body: |