tools: ynl-gen: re-sort ignoring recursive nests

We try to keep the structures and helpers "topologically sorted",
to avoid forward declarations. When recursive nests are at play
we need to sort twice, because structs which end up being marked
as recursive will get a full set of forward declarations, so we
should ignore them for the purpose of sorting.

Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20231213231432.2944749-7-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>