deps: Update korthout/backport-action action to v3.4.1

Author: renovate[bot]

.github/workflows/backport.yml

@@ -11,7 +11,7 @@ jobs:
         with:
           fetch-depth: 0
       - name: Create backport PRs
-        uses: korthout/backport-action@v3.2.1
+        uses: korthout/backport-action@v3.4.1
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           github_workspace: ${{ github.workspace }}