Add Dependabot auto-merge workflow

.github/workflows/dependabot-auto-merge.yml

@@ -0,0 +1,37 @@
+name: Dependabot Auto Merge
+
+on:
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  dependabot-auto-merge:
+    name: Dependabot Auto Merge
+    if: github.actor == 'dependabot'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Dependabot metadata
+        id: metadata
+        uses: dependabot/fetch-metadata@v1
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Wait for CI tests to pass
+        uses: kachick/wait-other-jobs@v1
+        timeout: 60m
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Enable auto-merge
+        if: steps.metadata.outputs.update-type != 'version-update:semver-major'
+        run: |
+          gh pr merge --admin --auto "${{ github.event.pull_request.number }}"
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}