ci: Add Dependabot dependency updates

Author: YasharF

.github/dependabot.yml

@@ -0,0 +1,30 @@
+version: 2
+updates:
+  - package-ecosystem: npm
+    directory: '/'
+    schedule:
+      interval: 'weekly'
+      day: 'thursday'
+    target-branch: 'master'
+    open-pull-requests-limit: 3
+    versioning-strategy: increase
+    commit-message:
+      prefix: 'chore'
+      include: 'scope'
+    groups:
+      major-updates:
+        update-types: ['major']
+      minor-updates:
+        update-types: ['minor']
+      patch-updates:
+        update-types: ['patch']
+
+  - package-ecosystem: 'github-actions'
+    directory: '/'
+    schedule:
+      interval: 'monthly'
+    target-branch: 'master'
+    open-pull-requests-limit: 3
+    commit-message:
+      prefix: 'chore'
+      include: 'scope'

.github/workflows/node.js.yml

@@ -9,7 +9,6 @@ on:
 permissions:
   contents: read
   pull-requests: write
-  security-events: write
 
 jobs:
   build:
@@ -18,7 +17,7 @@ jobs:
       matrix:
         node-version: [22.x]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Use Node.js ${{ matrix.node-version }}
         uses: actions/setup-node@v4
         with:
@@ -27,3 +26,20 @@ jobs:
       - run: npm install
       - run: npm run lint-check
       - run: npm run test
+
+  dependabot-automerge:
+    needs: [build]
+    if: >
+      github.event_name == 'pull_request' &&
+      github.event.pull_request.user.login == 'dependabot[bot]'
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      pull-requests: write
+    steps:
+      - name: Automerge Dependabot PRs if all checks have passed
+        shell: bash
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          gh pr merge --squash --auto ${{ github.event.pull_request.number }}