Docs/translations/ko_KR: remove memory-barriers

Docs/translations/ko_KR: remove memory-barriers

The memory-barriers.txt Korean translation is quite outdated.  The last
update on the translation was made on 2022-10-10, by commit ee5a86f451f7
("docs/memory-barriers.txt/kokr: Fix confusing name of 'data dependency
barrier'").  After the date, the original memory-barriers.txt got seven
more changes so far.  The most recent one was made on 2025-11-05.  But
none of those are applied to the translation.

Maybe I can work again on keeping it updated.  But, given the
advancement of translation tools, I think it might not be worth keeping
it at all.  Remove the outdated translation.

If it turns out to be worthy to keep the translation and someone willing
to keep it updated steps up, this could be reverted.

This change was inspired from the last kernel summit discussion [1].

[1] https://lpc.events/event/19/contributions/2259/

Cc: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: SeongJae Park <sj@kernel.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20251225014027.15948-1-sj@kernel.org>