ci: switch dependency testing to special target

.github/workflows/test.yml

@@ -5,16 +5,11 @@ on: [push, pull_request]
 jobs:
   build:
     if: "!contains(github.event.head_commit.message, '[skip ci]')"
-    name: ${{ matrix.config.name }}
     runs-on: "macos-latest"
     steps:
     - uses: actions/checkout@v1
 
-    - name: Prepare
-      run: |
-        ./build.py --target=clean-deps
-
     - name: Run tests
       run: |
         # Remove SDKROOT when 11.0+ SDK will become the default one
-        SDKROOT=/Library/Developer/CommandLineTools/SDKs/MacOSX11.0.sdk test/test.py
+        SDKROOT=/Library/Developer/CommandLineTools/SDKs/MacOSX11.0.sdk ./build.py --target=test-deps