Try a workflow to merge dependabot PRs

.github/workflows/dependabot.yml

@@ -0,0 +1,24 @@
+name: dependabot
+on:
+  pull_request_target:
+jobs:
+  automerge:
+    runs-on: ubuntu-latest
+    if: ${{ github.actor == 'dependabot[bot]' }}
+    steps:
+      - name: Dependabot metadata
+        uses: dependabot/fetch-metadata@4de7a6c08ce727a42e0adbbdc345f761a01240ce # v1.3.6
+        id: metadata
+      - name: Wait for status checks
+        uses: lewagon/wait-on-check-action@e106e5c43e8ca1edea6383a39a01c5ca495fd812 # v1.3.1
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          check-regexp: 'make \(check, .*\)'
+          wait-interval: 30
+      - name: Auto-merge for Dependabot PRs
+        if: ${{ steps.metadata.outputs.update-type == 'version-update:semver-minor' || steps.metadata.outputs.update-type == 'version-update:semver-patch'}}
+        run: gh pr merge --auto --rebase "$PR_URL"
+        env:
+          PR_URL: ${{github.event.pull_request.html_url}}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}