This introduced a performance regession. While it is true that
fnmatch already uses functools.lru_cache, that cache is limited to 256
on python 3.10 and older and we have over 1000 matching patterns, which
means the cache is evicted entirely on every iteration.

This reverts commit 951c894ab23537be90fbf3973d0345591e682371.

These are irrelevant because the fnmatch module implementation already
uses functools.lru_cache.

pyupgrade is a tool to automatically upgrade syntax for newer versions
of the Python language.

The project has been Python 3 only since
35544e2fc6eed0ce4a27ec7285aac71ff0ddc473, allowing for several cleanups:

- Remove unnecessary "-*- coding: utf-8 -*-" cookie. Python 3 reads all
  source files as utf-8 by default.

- Replace IOError/EnvironmentError with OSError. Python 3 unified these
  exceptions. The old names are aliases only.

- Use the Python 3 shorter super() syntax.

- Remove "utf8" argument form encode/decode. In Python 3, this value is
  the default.

- Remove "r" from open() calls. In Python 3, this value is the default.

- Remove u prefix from Unicode strings. In Python 3, all strings are
  Unicode.

- Replace io.open() with builtin open(). In Python 3, these functions
  are functionally equivalent.

Co-authored-by: Matthäus G. Chajdas <Anteru@users.noreply.github.com>

* Remove Python 2 compatibility

* remove 2/3 shims in pygments.util
* update setup.py metadata

* Remove unneeded object inheritance.

* Remove unneeded future imports.