ci: add cargo cache for faster builds

Author: Dario

.github/workflows/ci.yaml

@@ -12,6 +12,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@stable
+      - uses: Swatinem/rust-cache@v2
       - name: Check formatting
         run: cargo fmt --check
       - name: Clippy
@@ -36,6 +37,9 @@ jobs:
       - uses: dtolnay/rust-toolchain@stable
         with:
           targets: ${{ matrix.target }}
+      - uses: Swatinem/rust-cache@v2
+        with:
+          cache-on-failure: true
       - name: Build
         run: cargo build --release --target ${{ matrix.target }}
       - name: Upload binary