ci: Update to version 4 of actions/cache (#24)

Author: mantono

.github/workflows/rust.yml

@@ -18,21 +18,19 @@ jobs:
       fail-fast: false
     steps:
       - uses: actions/checkout@v1
-      - uses: actions/cache@v3
+      - uses: actions/cache@v4
+        id: cache-cargo-fetch
         with:
-          path: |
-            ~/.cargo/bin/
-            ~/.cargo/registry/index/
-            ~/.cargo/registry/cache/
-            ~/.cargo/git/db/
-            target/
-          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+          key: ${{ runner.os }}-cargo-fetch-${{ hashFiles('Cargo.lock') }}
+          path: target
+          restore-keys: ${{ runner.os }}-cargo-fetch
       - name: Fetch Dependencies
+        if: steps.cache-cargo-fetch.outputs.cache-hit != 'true'
         run: cargo fetch
       - name: Build
         run: cargo build --all-features
       - name: Run tests
-        run: cargo test --workspace
+        run: cargo test
 
   lint:
     runs-on: ubuntu-latest