Missing requirement of typing-extensions on python <= 3.10

[rokm]

On python versions that do not provide typing.Self (i.e., python <= 3.10), schwifty falls back to using typing_extensions. However, it does not specify typing-extensions as a requirement, and consequently user installing schwifty in a clean virtual environment will end up with defunct version. For example, on linux:

python3.10 -m venv venv
. venv/bin/activate
pip install schwifty
python -c "import schwifty" 

Traceback (most recent call last):
  File "[...]/venv/lib64/python3.10/site-packages/schwifty/common.py", line 9, in <module>
    from typing import Self
ImportError: cannot import name 'Self' from 'typing' (/usr/lib64/python3.10/typing.py)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "[...]/venv/lib64/python3.10/site-packages/schwifty/__init__.py", line 6, in <module>
    from schwifty.bban import BBAN
  File "[...]/venv/lib64/python3.10/site-packages/schwifty/bban.py", line 5, in <module>
    from schwifty import common
  File "[...]/lib64/python3.10/site-packages/schwifty/common.py", line 11, in <module>
    from typing_extensions import Self
ModuleNotFoundError: No module named 'typing_extensions'

[rokm]

Looks like aa251c2 accidentally removed "typing_extensions>=4.0; python_version <= '3.11'" requirement that was added in #201.

[mdomke]

@rokm Thanks for the heads-up. I published a new release 2024.05.2 to address the issue.