Auto-merge feature for dependabot PRs (#7300)

* Automerge for dependabot update

* change update period with daily, we can merge it automatically when `make check` of Ubuntu was passed

* Use rebase instead of merge commit

* check all Ubuntu jobs

.github/dependabot.yml

@@ -3,4 +3,4 @@ updates:
   - package-ecosystem: 'github-actions'
     directory: '/'
     schedule:
-      interval: 'monthly'
+      interval: 'daily'

.github/workflows/dependabot_automerge.yml

@@ -0,0 +1,26 @@
+# from https://github.com/gofiber/swagger/blob/main/.github/workflows/dependabot_automerge.yml
+name: Dependabot auto-merge
+on:
+  pull_request_target:
+
+jobs:
+  automerge:
+    runs-on: ubuntu-latest
+    if: ${{ github.actor == 'dependabot[bot]' }}
+    steps:
+      - name: Dependabot metadata
+        uses: dependabot/fetch-metadata@v1
+        id: metadata
+      - name: Wait for status checks
+        uses: lewagon/wait-on-check-action@v1.2.0
+        with:
+          repo-token: ${{ secrets.MATZBOT_GITHUB_TOKEN }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          check-regexp: "^Ubuntu"
+          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.MATZBOT_GITHUB_TOKEN }}