fix: update pyproject.toml with OSI approved license

[scottschreckengaust]

This will add the OSI approved license to the package

https://github.com/pypa/trove-classifiers/blob/7e3e9e0c1135492b5a630d60d8abac15fb1d81ee/src/trove_classifiers/__init__.py#L336C5-L336C68

[python-cla-bot]

The following commit authors need to sign the Contributor License Agreement:

• [email protected]

[brianschubert]

Hi! This trove classifier was in fact recently removed in #530. Using trove classifiers for license metadata was deprecated by PEP 639. Instead, typing_extensions now uses the PEP 639 License-Expression and License-File fields.

If you're suggesting this because a tool you're using doesn't work without the trove classifier, then the information in #559 and the issues linked therein may be helpful.

[scottschreckengaust]

Thank you @brianschubert #559 is helpful as I was looking at pip-licenses.