ci: Add a clippy check that only fails on errors.

Author: waywardmonkeys

.github/workflows/main.yml

@@ -150,6 +150,18 @@ jobs:
     - run: cargo check --lib
     - run: cargo check --lib --all-features
 
+  clippy:
+    name: Clippy
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Install Rust
+      run: |
+        rustup toolchain install stable --no-self-update --profile minimal --component rustfmt
+        rustup default stable
+      shell: bash
+    - run: cargo clippy
+
   rustfmt:
     name: Rustfmt
     runs-on: ubuntu-latest