Revert "Declare support for Python 3.11 (#2018) (#2019)"

This reverts commit adc1cc7.

2.14.2 will not be ready for python 3.11, we still need to support
exception groups.

Author: Pierre-Sassoulas

pyproject.toml

@@ -24,7 +24,6 @@ classifiers = [
     "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
-    "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: Implementation :: CPython",
     "Programming Language :: Python :: Implementation :: PyPy",
     "Topic :: Software Development :: Libraries :: Python Modules",