Fix GitHub Actions config

Author: Mitron57

.github/workflows/rust.yml

@@ -40,11 +40,13 @@ jobs:
       - name: Build benchmark
         uses: actions-rs/cargo@v1
         with:
+          working-directory: rust
           command: build
           args: --release --all-features
       - name: Run benchmark
         uses: actions-rs/cargo@v1
         with:
+          working-directory: rust
           command: bench
           args: --bench bench -- --output-format bencher | tee out.txt
       - name: Prepare benchmark results