Add Dependabot Auto Manage workflow

Signed-off-by: Mathias L. Baumann <[email protected]>

Author: Marenz

.github/workflows/auto-dependabot.yaml

@@ -0,0 +1,20 @@
+name: Dependabot Auto Manage
+on:
+  pull_request_target:
+    types: [opened, synchronize, reopened]
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  dependabot:
+    runs-on: ubuntu-latest
+    if: github.event.pull_request.user.login == 'dependabot[bot]' || github.event.pull_request.user.login == 'app/dependabot'
+    steps:
+      - uses: ad/dependabot-auto-approve@v1
+        with:
+          dependency-type: 'all'
+          auto-merge: 'true'
+          merge-method: 'merge'
+          add-label: 'auto-merged'