Deprecate License :: clasifiers

[befeleme]

PEP 639, provisionally accepted in August 2024, has deprecated the License classifiers in favor of the standardized License-Expression metadata field:
https://peps.python.org/pep-0639/#deprecate-license-classifiers

[di]

Thanks! Merging this will immediately make these classifiers deprecated, meaning that all uploads using them will be blocked (which is a lot).

Instead, we probably need to define a deprecation period which helps maintainers transition more smoothly to the new fields. I reopened pypi/warehouse#16620 accordingly and we should consider this PR blocked on that issue.

[ewdurbin]

I think this is beyond the scope of PEP 639, which just states that new license classifiers should not be added... not that existing classifiers should be marked as deprecated:

New license classifiers MUST NOT be added to PyPI; users needing them SHOULD use the License-Expression field instead. License classifiers may be removed from a new version of the specification in a future PEP.

[befeleme]

Thanks! Merging this will immediately make these classifiers deprecated, meaning that all uploads using them will be blocked (which is a lot).

Oh! I didn't know this is what deprecation means. This PR is then moot.