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]>

Author: dependabot[bot]

.github/workflows/sync_class_ref.yml

@@ -51,7 +51,7 @@ jobs:
           ./.engine-src/doc/tools/make_rst.py --color -o ./classes -l en ./.engine-src/doc/classes ./.engine-src/modules ./.engine-src/platform
 
       - name: Submit a pull-request
-        uses: peter-evans/create-pull-request@v5
+        uses: peter-evans/create-pull-request@v6
         with:
           commit-message: 'classref: Sync with current ${{ env.engine_rev }} branch (${{ steps.engine.outputs.rev_hash_short }})'
           branch: 'classref/sync-${{ steps.engine.outputs.rev_hash_short }}'