ci: add auto-merge workflow for Dependabot PRs

Author: RobThePCGuy

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

@@ -0,0 +1,20 @@
+name: Auto-merge Dependabot
+on: pull_request
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  auto-merge:
+    if: github.actor == 'dependabot[bot]'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: dependabot/fetch-metadata@v2
+        id: meta
+      - name: Auto-merge patch and minor updates
+        if: steps.meta.outputs.update-type != 'version-update:semver-major'
+        run: gh pr merge "$PR_URL" --auto --squash
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}