Remove license classifier

License classifiers are deprecated thanks to the existence of
`project.license`.

Fixes #292

Author: masklinn

pyproject.toml

@@ -28,7 +28,6 @@ classifiers = [
         "Environment :: Web Environment",
         "Intended Audience :: Developers",
         "Operating System :: OS Independent",
-        "License :: OSI Approved :: Apache Software License",
         "Programming Language :: Python",
         "Topic :: Internet :: WWW/HTTP",
         "Topic :: Software Development :: Libraries :: Python Modules",