ci: bump korthout/backport-action

Bumps the github-actions group with 1 update in the / directory: [korthout/backport-action](https://github.com/korthout/backport-action).


Updates `korthout/backport-action` from 4.2.0 to 4.3.0
- [Release notes](https://github.com/korthout/backport-action/releases)
- [Commits](4aaf0e03a9...3c06f323a5)

---
updated-dependencies:
- dependency-name: korthout/backport-action
  dependency-version: 4.3.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: github-actions
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/backport.yml

@@ -26,7 +26,7 @@ jobs:
 
       - name: Create backport PR
         id: backport
-        uses: korthout/backport-action@4aaf0e03a94ff0a619c9a511b61aeb42adea5b02 # v4.2.0
+        uses: korthout/backport-action@3c06f323a58619da1e8522229ebc8d5de2633e46 # v4.3.0
         with:
           pull_title: "${pull_title}"
           label_pattern: "^ci:backport ([^ ]+)$"