add rustfmt to nightly toolchain

Author: schell

.github/workflows/push.yaml

@@ -38,6 +38,7 @@ jobs:
           key: cargo-cache-${{ env.CARGO_GPU_COMMITSH }}-${{ runner.os }}
       - uses: moonrepo/setup-rust@v1
       - run: rustup default stable 
+      - run: rustup component add --toolchain nightly rustfmt
       - run: rustup update
       - run: | 
           cargo install --git https://github.com/rust-gpu/cargo-gpu --rev $CARGO_GPU_COMMITSH cargo-gpu