Bump unittest to 3.14 (#14012)

stdlib/@tests/stubtest_allowlists/py314.txt

@@ -202,22 +202,6 @@ turtle.poly
 turtle.save
 types.CodeType.co_branches
 types.FrameType.f_generator
-unittest.TestCase.assertEndsWith
-unittest.TestCase.assertHasAttr
-unittest.TestCase.assertIsSubclass
-unittest.TestCase.assertNotEndsWith
-unittest.TestCase.assertNotHasAttr
-unittest.TestCase.assertNotIsSubclass
-unittest.TestCase.assertNotStartsWith
-unittest.TestCase.assertStartsWith
-unittest.case.TestCase.assertEndsWith
-unittest.case.TestCase.assertHasAttr
-unittest.case.TestCase.assertIsSubclass
-unittest.case.TestCase.assertNotEndsWith
-unittest.case.TestCase.assertNotHasAttr
-unittest.case.TestCase.assertNotIsSubclass
-unittest.case.TestCase.assertNotStartsWith
-unittest.case.TestCase.assertStartsWith
 urllib.request.__all__
 urllib.request.FancyURLopener
 urllib.request.URLopener

stdlib/unittest/case.pyi

@@ -18,6 +18,7 @@ _T = TypeVar("_T")
 _S = TypeVar("_S", bound=SupportsSub[Any, Any])
 _E = TypeVar("_E", bound=BaseException)
 _FT = TypeVar("_FT", bound=Callable[..., Any])
+_SB = TypeVar("_SB", str, bytes, bytearray)
 _P = ParamSpec("_P")
 
 DIFF_OMITTED: Final[str]
@@ -289,6 +290,16 @@ class TestCase:
         # Runtime has *args, **kwargs, but will error if any are supplied
         def __init_subclass__(cls, *args: Never, **kwargs: Never) -> None: ...
 
+    if sys.version_info >= (3, 14):
+        def assertIsSubclass(self, cls: type, superclass: type | tuple[type, ...], msg: Any = None) -> None: ...
+        def assertNotIsSubclass(self, cls: type, superclass: type | tuple[type, ...], msg: Any = None) -> None: ...
+        def assertHasAttr(self, obj: object, name: str, msg: Any = None) -> None: ...
+        def assertNotHasAttr(self, obj: object, name: str, msg: Any = None) -> None: ...
+        def assertStartsWith(self, s: _SB, prefix: _SB | tuple[_SB, ...], msg: Any = None) -> None: ...
+        def assertNotStartsWith(self, s: _SB, prefix: _SB | tuple[_SB, ...], msg: Any = None) -> None: ...
+        def assertEndsWith(self, s: _SB, suffix: _SB | tuple[_SB, ...], msg: Any = None) -> None: ...
+        def assertNotEndsWith(self, s: _SB, suffix: _SB | tuple[_SB, ...], msg: Any = None) -> None: ...
+
 class FunctionTestCase(TestCase):
     def __init__(
         self,