`tarfile.TarFile` has several missing overloads

Right now TarFile.__init__ is defined as: https://github.com/python/typeshed/blob/c7e29eccd9759411c0f46580e20727038668b320/stdlib/tarfile.pyi#L128-L132

Which is not exactly right, because there's a case when name and fileobj are both None at the same time. And this will lead to runtime errors:

>>> import tarfile
>>> tarfile.TarFile(None, fileobj=None)
Traceback (most recent call last):
  File "<python-input-2>", line 1, in <module>
    tarfile.TarFile(None, fileobj=None)
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^
  File "/Users/sobolev/Desktop/cpython/Lib/tarfile.py", line 1729, in __init__
    fileobj = bltn_open(name, self._mode)
TypeError: expected str, bytes or os.PathLike object, not NoneType

Right now mypy does not raise any errors for this broken case: https://mypy-play.net/?mypy=latest&python=3.12&gist=7452d274249fafba1f8a16565d5486c6

We need either name or fileobj, they can be both None at the same time. So, we need to add overloads.

There are several other methods that needs to be updated like open and taropen, maybe others.

Inizia da stdlib/tarfile.pyi intorno alle righe 128-132 e rivedi le signature di TarFile.init, open e taropen. Riproduci la chiamata None/None con mypy usando l'esempio di playground collegato, quindi verifica che gli overload rappresentino le combinazioni valide di name/fileobj e diagnostica il caso non valido.