ci: add backports workflow

Author: mnaser

.github/workflows/backports.yaml

@@ -0,0 +1,34 @@
+name: backports
+
+on:
+  pull_request_target:
+    types: [closed]
+  issue_comment:
+    types: [created]
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  cherry-pick:
+    runs-on: ubuntu-latest
+    # NOTE(mnaser): https://github.com/korthout/backport-action?tab=readme-ov-file#trigger-using-a-comment
+    if: >
+      (
+        github.event_name == 'pull_request_target' &&
+        github.event.pull_request.merged
+      ) || (
+        github.event_name == 'issue_comment' &&
+        github.event.issue.pull_request &&
+        github.event.comment.user.id != 105816074 &&
+        startsWith(github.event.comment.body, '/backport')
+      )
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          token: ${{ secrets.VEXXHOST_BOT_PAT }}
+      - uses: korthout/backport-action@436145e922f9561fc5ea157ff406f21af2d6b363 # v3.2.0
+        with:
+          github_token: ${{ secrets.VEXXHOST_BOT_PAT }}
+          copy_labels_pattern: skip-release-notes