raft: leader resigns on the first encounter with `ER_WAL_IO`

[TarantoolBot]

Related dev. issue(s): tarantool/tarantool#9399

Product: Tarantool
Since: 3.1
Root document: https://www.tarantool.io/en/doc/latest/concepts/replication/repl_leader_elect/
SME: @ Astronomax

Details

Now the leader resigns on the first encounter with ER_WAL_IO write error (the leader broadcasts this).
Requested by @ Astronomax in tarantool/tarantool@0e71be2.