Big diff: use lower-case list and dict (#5888)

stdlib/unittest/suite.pyi

@@ -1,11 +1,11 @@
 import unittest.case
 import unittest.result
-from typing import Iterable, Iterator, List, Union
+from typing import Iterable, Iterator, Union
 
 _TestType = Union[unittest.case.TestCase, TestSuite]
 
 class BaseTestSuite(Iterable[_TestType]):
-    _tests: List[unittest.case.TestCase]
+    _tests: list[unittest.case.TestCase]
     _removed_tests: int
     def __init__(self, tests: Iterable[_TestType] = ...) -> None: ...
     def __call__(self, result: unittest.result.TestResult) -> unittest.result.TestResult: ...