doc:it_IT: remove unreferenced and not translated page

The netdev-FAQ page in the italian translation was creted to avoid
having broken links. With the evolution of the documentation this was
not referenced anymore, but the page never removed.
Reported-by: Davide Benini <davide.benini@gmail.com>
Signed-off-by: Federico Vaga <federico.vaga@vaga.pv.it>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240209222115.31505-1-federico.vaga@vaga.pv.it

Documentation/translations/it_IT/networking/netdev-FAQ.rst

-.. include:: ../disclaimer-ita.rst
-
-:Original: :ref:`Documentation/process/maintainer-netdev.rst <netdev-FAQ>`
-
-.. _it_netdev-FAQ:
-
-==========
-netdev FAQ
-==========
-
-.. warning::
-
-    TODO ancora da tradurre