Adjust pyproject.toml to force setuptools to emit valid metadata

When any of the glob patterns specified in the provisional field
"license-files" in the "tool.setuptools" section in pyproject.toml
matches a file in the package, Setuptools emits a License-File
metadata entry. However, Setuptools sets the Metadata-Version to 2.1.

With the implementation of PEP 639 and metadata version 2.4, this
combination is now invalid and is rejected by packaging, and thus by
PyPI.

Reset tools.setuptools.license-files to do not match any file. This
prevents invalid metadata to be generated.

pyproject.toml

@@ -70,7 +70,7 @@ packages = [
 	"twine.commands",
 ]
 include-package-data = true
-license-files = ["LICENSE"]
+license-files = []
 
 [tool.setuptools_scm]