Merge branch 'net-speedup-some-nexthop-handling-when-having-a-lot-of-nexthops'

Christoph Paasch says:

====================
net: Speedup some nexthop handling when having A LOT of nexthops

Configuring a very large number of nexthops is fairly possible within
a reasonable time-frame. But, certain netlink commands can become
extremely slow.

This series addresses some of these, namely dumping and removing
nexthops.

v1: https://lore.kernel.org/20250724-nexthop_dump-v1-1-6b43fffd5bac@openai.com
====================

Link: https://patch.msgid.link/20250816-nexthop_dump-v2-0-491da3462118@openai.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>