feat(ci): add dependabot auto-merge for patch and minor updates

Author: markuslf

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

@@ -0,0 +1,25 @@
+name: "Linuxfabrik: Dependabot auto-merge"
+
+on:
+  pull_request:
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  auto-merge:
+    runs-on: ubuntu-latest
+    if: github.actor == 'dependabot[bot]'
+    steps:
+
+      - uses: dependabot/fetch-metadata@v2
+        id: meta
+
+      - if: >-
+          steps.meta.outputs.update-type == 'version-update:semver-patch'
+          || steps.meta.outputs.update-type == 'version-update:semver-minor'
+        run: gh pr merge --auto --squash "$PR_URL"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}