doc: translations: sync translations 'remove info about -git patches'

Synchonise translations: CN, IT, JP, KR

commit 2c71d305 ("docs: process: Remove outdated info about -git patches")

I can guarantee for the Italian translations, but since we are removing
an entire chapter I think I did it right also for the other languages.

Signed-off-by: Federico Vaga <federico.vaga@vaga.pv.it>
Acked-by: SeongJae Park <sj38.park@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>