Typo: TestUmaskOf -> TestUmaskContext

Author: jb2170

Lib/test/test_shutil.py

@@ -3468,7 +3468,7 @@ def test_module_all_attribute(self):
 
 @unittest.skipIf(os.name != "posix" or support.is_wasi or support.is_emscripten,
                  "need proper os.umask()")
-class TestUmaskOf(unittest.TestCase):
+class TestUmaskContext(unittest.TestCase):
     # make target masks in here sufficiently exotic, away from 0o022
 
     mask_private = 0o777