Add dependabot automerge workflow

.github/workflows/dependabot-automerge.yml

@@ -0,0 +1,25 @@
+name: 'Automerge Dependabot'
+
+on:
+  pull_request_target:
+    types: [ opened, reopened ]
+    branches:
+    - dev
+    - master
+
+concurrency:
+  group: "dependabot-automerge-${{ github.head_ref || github.run_id }}-${{ github.event_name }}"
+  cancel-in-progress: true
+
+jobs:
+  automerge:
+    name: Enable Automerge on Dependabot PRs
+    runs-on: ubuntu-latest
+    if: github.event.pull_request.user.id == 49699333
+    permissions:
+      pull-requests: write
+    steps:
+      - name: Enable Automerge
+        uses: daneden/enable-automerge-action@f8558b65c5b8d8bfb592c4e74e3d491624a38fbd #v1.0.2-ish
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}