Remove license classifier

License classifiers are deprecated in favor of SPDX license expressions.

Author: hannesbraun

setup.py

@@ -15,7 +15,6 @@
 classifiers = """\
 Development Status :: 5 - Production/Stable
 Intended Audience :: Developers
-License :: OSI Approved :: MIT License
 Programming Language :: Python
 Programming Language :: Python :: 3
 Programming Language :: Python :: 3.9