build(deps): bump the ci group with 1 update

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

- [Release notes](https://github.com/korthout/backport-action/releases)
- [Commits](korthout/backport-action@bf5fdd6...bd68141)

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

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

Author: dependabot[bot]

.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@bf5fdd624b35f95d5b85991a728bd5744e8c6cf2 # v1.3.1
+        uses: korthout/backport-action@bd68141f079bd036e45ea8149bc9d174d5a04703 # v1.4.0
         # xref: https://github.com/korthout/backport-action#inputs
         with:
           # Use token to allow workflows to be triggered for the created PR