try github cache action instead

.github/workflows/ci.yml

@@ -100,6 +100,13 @@ jobs:
           toolchain: stable
           target: ${{ matrix.target }}
           override: true
+      - uses: actions/cache@v2
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            target
+          key: ${{ runner.os }}-${{ matrix.target }}-cargo-${{ hashFiles('**/Cargo.lock') }}
       # - name: Rust Cache
       #   uses: Swatinem/rust-cache@v1.2.0
       # - name: Install PowerPC GCC