Add workflow job for running clippy on codebase

Signed-off-by: Matthias Beyer <mail@beyermatthias.de>

.github/workflows/rust.yml

@@ -20,3 +20,15 @@ jobs:
       run: cargo build --verbose
     - name: Run tests
       run: cargo test --verbose
+
+  clippy:
+    needs: [build]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: 1.65.0
+          components: clippy
+      - run: cargo clippy -- -D warnings
+