Fix: typevar with default cause error in typing-extensions<4.11.0

[gouzil]

In versions prior to typing-extensions 4.11.0, the following error occurs

Traceback (most recent call last):
  File "/Users/user/Documents/git/paddle-tools/autoTable/test.py", line 1, in <module>
    from githubkit import GitHub
  File "/Users/user/miniconda3/envs/py312/lib/python3.12/site-packages/githubkit/__init__.py", line 17, in <module>
    from .core import GitHubCore as GitHubCore
  File "/Users/user/miniconda3/envs/py312/lib/python3.12/site-packages/githubkit/core.py", line 44, in <module>
    class GitHubCore(Generic[A]):
  File "/Users/user/miniconda3/envs/py312/lib/python3.12/site-packages/githubkit/core.py", line 342, in GitHubCore
    ) -> Response[T]: ...
         ~~~~~~~~^^^
  File "/Users/user/miniconda3/envs/py312/lib/python3.12/typing.py", line 384, in inner
    return func(*args, **kwds)
           ^^^^^^^^^^^^^^^^^^^
  File "/Users/user/miniconda3/envs/py312/lib/python3.12/typing.py", line 1066, in _generic_class_getitem
    _check_generic(cls, params, len(cls.__parameters__))
  File "/Users/user/miniconda3/envs/py312/lib/python3.12/typing.py", line 304, in _check_generic
    raise TypeError(f"Too {'many' if alen > elen else 'few'} arguments for {cls};"
TypeError: Too few arguments for <class 'githubkit.response.Response'>; actual 1, expected 2

Duplicate code

from githubkit import GitHub

[yanyongyu]

This error is fixed in the python/typing_extensions#293 . so we should increase the minimum required typing-extensions version.