add auto merge

Author: branchv

src/.github/dependabot.yaml

@@ -5,7 +5,11 @@ updates:
     directory: "/"
     schedule:
       interval: "weekly"
+    labels:
+      - automerge
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule:
       interval: "weekly"
+    labels:
+      - automerge

src/.github/workflows/automerge.yaml

@@ -0,0 +1,18 @@
+name: Automerge
+
+on:
+  pull_request:
+    types: [opened, synchronize, labeled, reopened]
+
+jobs:
+  automerge:
+    if: contains(github.event.pull_request.labels.*.name, 'automerge')
+    runs-on: ubuntu-latest
+    steps:
+      - name: Merge PR
+        run: |
+          gh pr merge --auto --squash --body="[ci skip]" "$PR_URL"
+          gh pr review --approve "$PR_URL"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}