Update Rust build target in GitHub workflow

The target file for the Rust build in the GitHub workflow has been changed from 'backend-rust' to 'authnz-rs'. This update also applies to the stripping and upload actions.

.github/workflows/rust.yaml

@@ -45,9 +45,9 @@ jobs:
           source $HOME/.cargo/env
           rustup target add ${{ matrix.target }}
           cargo build --release --target ${{ matrix.target }}
-          strip target/${{ matrix.target }}/release/backend-rust
+          strip target/${{ matrix.target }}/release/authnz-rs
       - name: Upload artifact
         uses: actions/upload-artifact@v4
         with:
           name: ${{ matrix.target }}-build
-          path: target/${{ matrix.target }}/release/backend-rust
+          path: target/${{ matrix.target }}/release/authnz-rs