Run stubtest_unused on Darwin (#5410)

Fixes #5405

Co-authored-by: hauntsaninja <>

.github/workflows/stubtest-unused-whitelist.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: ["ubuntu-latest", "windows-latest"]
+        os: ["ubuntu-latest", "windows-latest", "macos-latest"]
         python-version: [3.6, 3.7, 3.8, 3.9, '3.10.0-beta.1']
       fail-fast: false