Add Dependabot auto-merge configuration

.github/dependabotautomerge.yml

@@ -0,0 +1,27 @@
+name: Auto-merge Dependabot PRs
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  automerge:
+    if: github.actor == 'dependabot[bot]'
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check for auto-merge label
+        id: check
+        run: |
+          labels=$(jq -r '.pull_request.labels[].name' "$GITHUB_EVENT_PATH")
+          echo "labels=$labels" >> $GITHUB_OUTPUT
+
+      - name: Auto-merge
+        if: contains(steps.check.outputs.labels, 'auto-merge')
+        uses: fastify/github-action-merge-dependabot@v3
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}