ci: Add cargo fmt job

.github/workflows/ci.yaml

@@ -21,3 +21,20 @@ jobs:
         run: |
           echo 'TOML is not formatted correctly'
           echo 'Please run `taplo format`'
+
+  format:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+      - name: List version
+        run: |
+          cargo --version
+          cargo fmt --version
+      - name: Cargo format
+        run: cargo fmt --all -- --check
+      - name: Cargo fmt failure info
+        if: failure()
+        run: |
+          echo '.rs files are not formatted correctly'
+          echo 'Please run `cargo fmt --all`'