Add 'needs cherry pick' label to auto-create cherrypick PRs (nginx#5796)

Author: oseoin

.github/workflows/cherry-pick.yml

@@ -15,7 +15,7 @@ jobs:
       pull-requests: write
     runs-on: ubuntu-22.04
     name: Cherry pick into release branch
-    if: ${{ contains(github.event.pull_request.labels.*.name, 'dependencies') && github.event.pull_request.merged == true }}
+    if: ${{ (contains(github.event.pull_request.labels.*.name, 'dependencies') || contains(github.event.pull_request.labels.*.name, 'needs cherry pick')) && github.event.pull_request.merged == true }}
     steps:
       - name: Checkout
         uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29 # v4.1.6