[ci] Enable Concurrency Runtime tests on CI

Author: kateinoigakukun

.github/workflows/build-toolchain.yml

@@ -137,6 +137,8 @@ jobs:
           TARGET_STDLIB_BUILD_DIR=${{ github.workspace }}/target-build/swift-stdlib-wasi-wasm32
           ./swift/utils/run-test --build-dir "$TARGET_STDLIB_BUILD_DIR" --target wasi-wasm32 \
             "$TARGET_STDLIB_BUILD_DIR/test-wasi-wasm32/stdlib"
+          ./swift/utils/run-test --build-dir "$TARGET_STDLIB_BUILD_DIR" --target wasi-wasm32 \
+            "$TARGET_STDLIB_BUILD_DIR/test-wasi-wasm32/Concurrency/Runtime"
 
       - name: Run all tests for wasi-wasm32
         if: ${{ matrix.run_full_test }}