Merge branch 'af_unix-clean-up-headers'

Kuniyuki Iwashima says:

====================
af_unix: Clean up headers.

AF_UNIX files include many unnecessary headers (netdevice.h and
rtnetlink.h, etc), and this series cleans them up.

Note that there are still some headers included indirectly and
modifying them triggers rebuild, which seems mostly inevitable. [0]

  $ python3 include_graph.py net/unix/garbage.c linux/rtnetlink.h linux/netdevice.h
  ...
  include/net/af_unix.h
  | include/linux/net.h
  | | include/linux/once.h
  | | include/linux/sockptr.h
  | | include/uapi/linux/net.h
  | include/net/sock.h
  | | include/linux/netdevice.h   <---
  ...
  | | include/net/dst.h
  | | | include/linux/rtnetlink.h <---

[0]: https://gist.github.com/q2ven/9c5897f11a493145829029c0bfb364d0
====================

Link: https://patch.msgid.link/20250318034934.86708-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>