ci: don't add -D warnings rust flags

Signed-off-by: Henry Gressmann <[email protected]>

Author: explodingcamera

.github/workflows/test.yaml

@@ -20,6 +20,7 @@ jobs:
         uses: actions-rust-lang/setup-rust-toolchain@v1
         with:
           toolchain: stable
+          rustflags: ""
           target: wasm32-unknown-unknown
       - name: Install Binaryen and WABT
         run: sudo apt-get install -y binaryen wabt