github: configure dependapot with automatic merging

.github/dependabot.yml

@@ -0,0 +1,26 @@
+# Basic test trying dependabot
+---
+version: 2
+updates:
+
+  # Maintain dependencies for GitHub Actions
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+      time: "04:00"
+    open-pull-requests-limit: 5
+    rebase-strategy: "disabled"
+
+  # Maintain dependencies for Go
+  - package-ecosystem: "gomod"
+    directory: "/odc"
+    schedule:
+      interval: "daily"
+      time: "04:00"
+    groups:
+      go-deps:
+        patterns:
+          - "*"  # group all dependency updates into one PR
+    open-pull-requests-limit: 1
+    rebase-strategy: "auto"

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

@@ -0,0 +1,23 @@
+# Taken from https://docs.github.com/en/code-security/dependabot/working-with-dependabot/automating-dependabot-with-github-actions#common-dependabot-automations
+
+name: Dependabot auto-approve and auto-merge
+on: pull_request_target
+
+permissions: write-all
+
+jobs:
+  dependabot:
+    runs-on: ubuntu-latest
+    if: ${{ github.actor == 'dependabot[bot]' }}
+    steps:
+      - name: Approve a PR
+        run: gh pr review --approve "$PR_URL"
+        env:
+          PR_URL: ${{github.event.pull_request.html_url}}
+          GITHUB_TOKEN: ${{secrets.SCHUTZBOT_GITHUB_ACCESS_TOKEN}}
+
+      - name: Enable auto-merge for Dependabot PRs
+        run: gh pr merge --auto --rebase "$PR_URL"
+        env:
+          PR_URL: ${{github.event.pull_request.html_url}}
+          GITHUB_TOKEN: ${{secrets.SCHUTZBOT_GITHUB_ACCESS_TOKEN}}