Sorry to revive this, but the wording in PEP 639 is breaking some projects which have a need to fetch the LICENSE file from a parent directory (because the Python bindings are part of a larger project).
It is not obvious how to workaround this problem in the package configuration. Am I missing something?
See [Request for Reverting Intentional Breaking Change] New license file validation breaks projects with non-standard layout · Issue #4892 · pypa/setuptools · GitHub for the corresponding setuptools GH issue.