Fix cibw_test_skip typo

Author: alugowski

.github/workflows/wheels.yml

@@ -93,7 +93,7 @@ jobs:
           - os: macos-14
             cibw_archs: "arm64"
             # Silence warning for only Python 3.8, as per https://github.com/pypa/cibuildwheel/pull/1169
-            cibw_skip: "cp38-macosx_*:arm64"
+            cibw_test_skip: "cp38-macosx_*:arm64"
 
     steps:
       - uses: actions/checkout@v4