The series contains small fixes to the gossiper one of which fixes#21930. Others I noticed while debugged the issue.
Fixes: #21930
(cherry picked from commit 91cddcc17f)
Parent PR: #21956Closesscylladb/scylladb#21991
* github.com:scylladb/scylladb:
gossiper: do not reset _just_removed_endpoints in non raft mode
gossiper: do not call apply for the node's old state