net: sched: Remove NET_ACT_IPT from Kconfig

After this commit ba24ea12 ("net/sched: Retire ipt action")
NET_ACT_IPT is not needed anymore as the action is retired and the code
is removed.

Clean the Kconfig part as well.

Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20240209180656.867546-1-harshit.m.mogalapalli@oracle.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>