add rust-src component for wasm compilation

Author: x3c41a

.github/workflows/smoldot-test.yml

@@ -28,6 +28,7 @@ jobs:
         uses: dtolnay/rust-toolchain@stable
         with:
           targets: wasm32-unknown-unknown
+          components: rust-src
 
       - name: Install system dependencies
         run: |