CI: add clippy

Author: newAM

.github/workflows/ci.yml

@@ -37,3 +37,12 @@ jobs:
           components: rustfmt
       - name: cargo fmt --check
         run: cargo fmt --all -- --check
+
+  clippy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          components: clippy
+      - run: cargo clippy --all --all-targets -- --deny warnings