Loading the gossip_store would not create a pending node announcement
when the node already had a zombie channel. This would cause the node
announcement to attempt to be loaded, but fail because it had no
broadcastable channels. Accepting a pending node announcement as when
normally loading from the channel corrects this.
`node_has_public_channels` taking into account zombie channels enables
this behavior.
Separately, node_announcements were still being flagged as zombies
in the gossip store despite that feature being removed.
Changelog-None