.github: Fix CI by first building the frontend

.github/workflows/build.yml

@@ -10,11 +10,19 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
+
     - uses: dtolnay/rust-toolchain@stable
+
     - name: Check code style
       run: cargo fmt -- --check
+
+    - name: Build Frontend
+      working-directory: src/webpage
+      run: trunk build --release --locked --verbose
+
     - name: Build
-      run: cargo build --verbose
+      run: SKIP_FRONTEND=1 cargo build --verbose
+
     - name: Test
       run: cargo test --verbose -- --nocapture