ci: automerge updates to dependencies after running tests (#239)

Author: zimeg

.github/workflows/dependencies.yml

@@ -4,6 +4,31 @@ on:
     - cron: "0 0 * * *"
   workflow_dispatch:
 jobs:
+  dependabot:
+    name: "@dependabot"
+    if: github.event.pull_request.user.login == 'dependabot[bot]'
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
+    steps:
+      - name: Collect metadata
+        id: metadata
+        uses: dependabot/fetch-metadata@08eff52bf64351f401fb50d4972fa95b9f2c2d1b # v2.4.0
+        with:
+          github-token: "${{ secrets.GITHUB_TOKEN }}"
+      - name: Approve
+        if: steps.metadata.outputs.update-type == 'version-update:semver-patch' || steps.metadata.outputs.update-type == 'version-update:semver-minor'
+        run: gh pr review --approve "$PR_URL"
+        env:
+          PR_URL: ${{github.event.pull_request.html_url}}
+          GH_TOKEN: ${{secrets.GITHUB_TOKEN}}
+      - name: Automerge
+        if: steps.metadata.outputs.update-type == 'version-update:semver-patch' || steps.metadata.outputs.update-type == 'version-update:semver-minor'
+        run: gh pr merge --auto --squash "$PR_URL"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
   golang:
     name: Bump the Golang version
     runs-on: ubuntu-latest