Fix working directory

.github/workflows/build.yml

@@ -5,14 +5,16 @@ jobs:
   build:
     name: Build
     runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: ./frontend
     steps:
       - uses: actions/checkout@v3
 
       - name: Set Node.js 16.x
         uses: actions/setup-node@v3
         with:
           node-version: 16.x
-
       - name: Run install
         uses: borales/actions-yarn@v4
         with: