fix a parallel creation of temp_cwd

Author: qunaibit

graalpython/lib-python/3/test/support/__init__.py

@@ -1082,7 +1082,7 @@ def change_cwd(path, quiet=False):
 
 
 @contextlib.contextmanager
-def temp_cwd(name='tempcwd', quiet=False):
+def temp_cwd(name=None, quiet=False): # GR-27905
     """
     Context manager that temporarily creates and changes the CWD.