Updated tests for cfg flags. and added CI for flagging

Author: RPG-Alex

.github/workflows/rust.yml

@@ -48,13 +48,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-
       - name: Install Rust
         uses: dtolnay/rust-toolchain@stable
-
       - name: Check no_std build
         run: cargo check --no-default-features
-
       - name: Test no_std build
         run: cargo test --no-default-features