Add dependabot config and automerge

Signed-off-by: Alexandre Terrasa <[email protected]>

.github/dependabot.yml

@@ -0,0 +1,26 @@
+version: 2
+updates:
+  - package-ecosystem: "bundler"
+    directory: "/"
+    schedule:
+      interval: "monthly"
+    reviewers:
+      - "Shopify/sorbet"
+    labels:
+      - "dependencies"
+  - package-ecosystem: "bundler"
+    directory: "/gem"
+    schedule:
+      interval: "monthly"
+    reviewers:
+      - "Shopify/sorbet"
+    labels:
+      - "dependencies"
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    reviewers:
+      - "Shopify/sorbet"
+    labels:
+      - "dependencies"

.github/workflows/dependabot_automerge.yml

@@ -0,0 +1,65 @@
+name: Dependabot auto-merge
+on: pull_request_target
+
+permissions:
+  pull-requests: write
+  contents: write
+
+jobs:
+  dependabot:
+    runs-on: ubuntu-latest
+    if: ${{ github.event.pull_request.user.login == 'dependabot[bot]' && github.actor == 'dependabot[bot]' }}
+    steps:
+      - name: Dependabot metadata
+        id: metadata
+        uses: dependabot/[email protected]
+        with:
+          github-token: "${{ secrets.GITHUB_TOKEN }}"
+      - name: Enable auto-merge for Dependabot PRs
+        if: ${{ steps.metadata.outputs.update-type != 'version-update:semver-major' }}
+        uses: actions/github-script@v7
+        with:
+          github-token: "${{ secrets.GITHUB_TOKEN }}"
+          script: |
+            const getPullRequestIdQuery = `query GetPullRequestId($owner: String!, $repo: String!, $pullRequestNumber: Int!) {
+              repository(owner: $owner, name: $repo) {
+                pullRequest(number: $pullRequestNumber) {
+                  id
+                }
+              }
+            }`
+            const repoInfo = {
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              pullRequestNumber: context.issue.number,
+            }
+            const response = await github.graphql(getPullRequestIdQuery, repoInfo)
+
+            await github.rest.pulls.createReview({
+              pull_number: context.issue.number,
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              event: 'APPROVE',
+            })
+
+            const enableAutoMergeQuery = `mutation ($pullRequestId: ID!, $mergeMethod: PullRequestMergeMethod!) {
+              enablePullRequestAutoMerge(input: {
+                pullRequestId: $pullRequestId,
+                mergeMethod: $mergeMethod
+              }) {
+                pullRequest {
+                  autoMergeRequest {
+                    enabledAt
+                    enabledBy {
+                      login
+                    }
+                  }
+                }
+              }
+            }`
+            const data = {
+              pullRequestId: response.repository.pullRequest.id,
+              mergeMethod: 'MERGE',
+            }
+
+            await github.graphql(enableAutoMergeQuery, data)