chore: simplify code after typing-extension dep

The dependency is now installed for Python 3.10 and 3.11 as well, allowing to
use it in the codebase for those versions.

src/bigxml/handle_mgr.py

@@ -1,3 +1,4 @@
+import sys
 from typing import (
     TYPE_CHECKING,
     Any,
@@ -20,16 +21,14 @@
 )
 from bigxml.utils import last_item_or_none
 
-if TYPE_CHECKING:
-    import sys
+if sys.version_info < (3, 11):  # pragma: no cover
+    from typing_extensions import Never
+else:  # pragma: no cover
+    from typing import Never
 
+if TYPE_CHECKING:
     from bigxml.nodes import XMLElement, XMLText
 
-    if sys.version_info < (3, 11):  # pragma: no cover
-        from typing import NoReturn as Never
-    else:  # pragma: no cover
-        from typing import Never
-
 
 class HandleMgr:
     _handle: Optional[

tests/integration/test_typing.py

@@ -1,6 +1,6 @@
 from dataclasses import dataclass
 import sys
-from typing import TYPE_CHECKING, Any, Iterable, Iterator, Optional, Tuple, Union
+from typing import Iterable, Iterator, Optional, Tuple, Union
 
 from bigxml import (
     HandlerTypeHelper,
@@ -12,16 +12,9 @@
 )
 
 if sys.version_info < (3, 11):
-    from typing import NoReturn as Never
+    from typing_extensions import Never, assert_type
 else:
-    from typing import Never
-
-if TYPE_CHECKING:
-    from typing_extensions import assert_type
-else:
-
-    def assert_type(val: Any, _: Any) -> Any:  # noqa: ANN401
-        return val
+    from typing import Never, assert_type
 
 
 # Note: the aim of this file is to test the typing of return-values