Apply clippy to tests and examples

Author: taiki-e

.github/workflows/ci.yml

@@ -58,7 +58,7 @@ jobs:
       - uses: actions/checkout@v3
       - name: Install Rust
         run: rustup update stable
-      - run: cargo clippy --all-features
+      - run: cargo clippy --all-features --tests --examples
 
   fmt:
     runs-on: ubuntu-latest