Merge branch 'selftest-netfilter-additional-cleanups'

Florian Westphal says:

====================
selftest: netfilter: additional cleanups

This is the last planned series of the netfilter-selftest-move.
It contains cleanups (and speedups) and a few small updates to
scripts to improve error/skip reporting.

I intend to route future changes, if any, via nf(-next) trees
now that the 'massive code churn' phase is over.
====================

Link: https://lore.kernel.org/r/20240423130604.7013-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>