chore(deps): bump korthout/backport-action from 2.5.0 to 3.1.0

Bumps [korthout/backport-action](https://github.com/korthout/backport-action) from 2.5.0 to 3.1.0.
- [Release notes](https://github.com/korthout/backport-action/releases)
- [Commits](korthout/backport-action@ef20d86...be567af)

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

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

.github/workflows/backport.yaml

@@ -20,7 +20,7 @@ jobs:
         with:
           ref: ${{ github.event.pull_request.head.sha }}
       - name: Create backport PRs
-        uses: korthout/backport-action@ef20d86abccbac3ee3a73cb2efbdc06344c390e5 # v2.5.0
+        uses: korthout/backport-action@be567af183754f6a5d831ae90f648954763f17f5 # v3.1.0
         # xref: https://github.com/korthout/backport-action#inputs
         with:
           # Use token to allow workflows to be triggered for the created PR