tests: py: remove verdict from closing end interval

tests: py: remove verdict from closing end interval

Kernel does not allow for NFT_SET_ELEM_INTERVAL_END flag and
NFTA_SET_ELEM_DATA. The closing end interval represents a mismatch,
therefore, no verdict can be applied. The existing payload files show
the drop verdict when this is unset (because NF_DROP=0).

This update is required to fix payload warnings in tests/py after
libnftnl's ("set: use NFTNL_SET_ELEM_VERDICT to print verdict").

Fixes: 6671d9d137f6 ("mnl: Set NFTNL_SET_DATA_TYPE before dumping set elements")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>