Add support for license.text

[cdce8p]

Before license expressions, the license table was allowed to contain a text key. That never got implemented even though the docs list it as supported. Map license.text to the License core metadata field.

flit/doc/pyproject_toml.rst

Lines 98 to 101 in 2818f41

	license
	A valid SPDX `license expression <https://peps.python.org/pep-0639/#term-license-expression>`_
	or a table with either a ``file`` key (a relative path to a license file) or a
	``text`` key (the license text).

It seems this was accidentally removed in f08bb9f

[takluyver]

Thanks, but I actually took it back out deliberately. It was never clear to me whether the project.license.text field was meant to contain a license name or the full text of the license, and I didn't want to mess up the metadata with the full text, especially since it wasn't really used for anything. Before the license expressions, the classifiers were the best way to add vaguely structured info about licenses. And it seems a bit weird to start adding that in just when it's deprecated.

Sorry not to be clearer about that and leave you redoing the change!

[cdce8p]

It was never clear to me whether the project.license.text field was meant to contain a license name or the full text of the license, and I didn't want to mess up the metadata with the full text, especially since it wasn't really used for anything.

Yeah, I agree that it was kind of confusing. The best way I've seen it used is actually with a SPDX license identifier itself, before just project.license was allowed / supported. Since the License metadata field is actually displayed on PyPI as well, that was quite useful.

Not really necessary now that license expressions will be officially supported.