build: use node instead of bun

.github/workflows/main.yaml

@@ -21,17 +21,17 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: oven-sh/setup-bun@v2
+      - uses: actions/setup-node@v6
 
       - name: Install dependencies
         working-directory: frontend/spa
-        run: bun install
+        run: npm install
 
       - name: Run tests
         working-directory: frontend/spa
         env:
           APP_ENV: testing
-        run: bun run test
+        run: npm run test
 
   test_backend:
     name: Run Backend tests
@@ -77,7 +77,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: oven-sh/setup-bun@v2
+      - uses: actions/setup-node@v6
 
       - name: Setup PHP 7.4
         uses: shivammathur/setup-php@v2