Use 'destroy' instead of creating and deleting table in nftables.conf

Description:

As an alternative to

table inet filter
delete table inet filter

on linux >= 6.3 it's possible to use

destroy table inet filter

This works like delete, but unlike delete, destroy will not return an error if the table did not already exist.

Additional info:

https://git.netfilter.org/nftables/commit/?id=e1dfd5cc4c46514a84dd8a2063b45517b596e1ca
https://wiki.nftables.org/wiki-nftables/index.php/List_of_updates_since_Linux_kernel_3.13#6.3