ci: parallelize unit test with matrix (#1833)

Author: kevinjqliu

.github/workflows/ci.yml

@@ -139,6 +139,13 @@ jobs:
 
   unit:
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        test-suite:
+          - { name: "default", args: "--all-targets --all-features --workspace" }
+          - { name: "smol", args: "--all-targets --no-default-features --features smol --features storage-all --workspace" }
+          - { name: "doc", args: "--doc --all-features --workspace" }
+    name: Unit Tests (${{ matrix.test-suite.name }})
     steps:
       - name: Maximize build space
         uses: easimon/maximize-build-space@master
@@ -163,15 +170,11 @@ jobs:
 
       - name: Cache Rust artifacts
         uses: Swatinem/rust-cache@v2
+        with:
+          key: ${{ matrix.test-suite.name }}
 
       - name: Test
-        run: cargo test --no-fail-fast --all-targets --all-features --workspace
-
-      - name: Smol Test
-        run: cargo test --no-fail-fast --all-targets --no-default-features --features "smol" --features "storage-all" --workspace
-
-      - name: Doc Test
-        run: cargo test --no-fail-fast --doc --all-features --workspace
+        run: cargo test --no-fail-fast ${{ matrix.test-suite.args }}
 
   msrv:
     name: Verify MSRV