Trim unused pygments formatters and CLI

[ichard26]

The formatters are exclusively used by the pygments CLI which is already broken because it depends on lexers we've trimmed a long time ago.

~/dev/oss/pip ❯ python -m pip._vendor.pygments
Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "/home/ichard26/dev/oss/pip/src/pip/_vendor/pygments/__main__.py", line 12, in <module>
    from pip._vendor.pygments.cmdline import main
  File "/home/ichard26/dev/oss/pip/src/pip/_vendor/pygments/cmdline.py", line 23, in <module>
    from pip._vendor.pygments.lexers.special import TextLexer
ModuleNotFoundError: No module named 'pip._vendor.pygments.lexers.special'

For context: while rich is great and it makes improving our CLI output much easier, we were never happy with how it ballooned the size of our vendored dependencies.

[pfmoore]

I merged the vendoring updates for 25.1 to ensure this won't have merge conflicts.

[ichard26]

Thanks for the reviews @pfmoore and @pradyunsg !