build(deps): bump korthout/backport-action from 3.4.1 to 4.0.1

Bumps [korthout/backport-action](https://github.com/korthout/backport-action) from 3.4.1 to 4.0.1.
- [Release notes](https://github.com/korthout/backport-action/releases)
- [Commits](d07416681c...c656f5d585)

---
updated-dependencies:
- dependency-name: korthout/backport-action
  dependency-version: 4.0.1
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
(cherry picked from commit 4227d24bc3)

.github/workflows/backport.yml

@@ -26,7 +26,7 @@ jobs:
           # required to find all branches
           fetch-depth: 0
       - name: Create backport PRs
-        uses: korthout/backport-action@d07416681cab29bf2661702f925f020aaa962997 # v3.4.1
+        uses: korthout/backport-action@c656f5d5851037b2b38fb5db2691a03fa229e3b2 # v4.0.1
         id: backport
         with:
           # Config README: https://github.com/korthout/backport-action#backport-action