Audit and fix unused `NameError` handlers

[sobolevn]

After d6f2767 I've decided to take a look at other unused / obsolete NameError items that can be removed.

This is what I found:

• tarfile.py: https://github.com/python/cpython/blame/26726c76494d85c7b565b764c732dd4473458409/Lib/tarfile.py#L61-L66 OSError is always defined. It used to be a WindowsError. Should be removed
• copyreg.py: https://github.com/python/cpython/blame/26726c76494d85c7b565b764c732dd4473458409/Lib/copyreg.py#L28-L37 complex is always defined, this code is 16 years old (it is finishing high school now). Should be removed

PR is on its way.

• PR: gh-99325: Remove unused NameError handling #99326

[AlexWaygood]

Thanks @sobolevn!