Implement depcheck as a Github Action

.github/workflows/depcheck.yml

@@ -0,0 +1,30 @@
+name: Depcheck
+
+on:
+  push:
+    branches:
+      - nextjs
+  pull_request:
+    branches:
+      - nextjs
+
+jobs:
+  check_dependencies:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v2
+        with:
+          node-version: 18
+
+      - name: Install yarn
+        run: npm install -g yarn
+
+      - name: Install depcheck
+        run: yarn global add depcheck
+
+      - name: Run depcheck
+        run: depcheck ./frontend --fail-on-error