Enable test_bitfields_ctypes_stdlib on macOS

Author: BCSharp

tests/IronPython.Tests/Cases/IronPythonCasesManifest.ini

@@ -185,9 +185,6 @@ RunCondition=$(IS_POSIX) # Module resource is Posix-specific
 IsolationLevel=PROCESS # https://github.com/IronLanguages/ironpython3/issues/489
 FullFrames=true
 
-[IronPython.modules.type_related.test_bitfields_ctypes_stdlib]
-RunCondition=NOT $(IS_OSX) # ctypes tests not prepared for macOS
-
 [IronPython.scripts.test_builder]
 Ignore=true