Automerge dependabot actions updates

This way trivial actions updates just land, and nobody has to do anything

.github/workflows/test.yml

@@ -1,6 +1,6 @@
 name: tests
 
-on: [push]
+on: [push, pull_request]
 
 jobs:
   test:
@@ -19,3 +19,12 @@ jobs:
         node-version: ${{ matrix.node-version }}
     - run: npm i
     - run: npm test
+
+  automerge:
+    needs: test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: fastify/[email protected]
+        if: ${{ github.actor == 'dependabot[bot]' && github.event_name == 'pull_request' && contains(github.head_ref, 'dependabot/github_actions') }}
+        with:
+          github-token: ${{secrets.github_token}}