Delete Python 2 extra (python#18374)

For mypy v2

Author: hauntsaninja

pyproject.toml

@@ -62,7 +62,6 @@ dynamic = ["version"]
 [project.optional-dependencies]
 dmypy = ["psutil>=4.0"]
 mypyc = ["setuptools>=50"]
-python2 = []
 reports = ["lxml"]
 install-types = ["pip"]
 faster-cache = ["orjson"]