Merge branch 'udplite-dccp-print-deprecation-notice'

Kuniyuki Iwashima says:

====================
udplite/dccp: Print deprecation notice.

UDP-Lite is assumed to have no users for 7 years, and DCCP is
orphaned for 7 years too.

Let's add deprecation notice and see if anyone responds to it.
====================

Link: https://lore.kernel.org/r/20230614194705.90673-1-kuniyu@amazon.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>