Add missing retries to the etcd-events ensure-member check (#13669)

The etcd twin of "Join Member | Ensure member is in etcd-events cluster"
retries the etcdctl member list check (retries/delay/until), the events
copy does not: a transient etcdctl failure right after the member was
added - exactly when the events cluster quorum is shifting - aborts the
play on etcd_events_cluster deployments while the main etcd path rides
the same blip out. Mirror the twin's retry block with the events register
variable. Second instance of the etcd/etcd-events task divergence; the
first was #13640.

Signed-off-by: longyuxiang <longyuxiang@kylinos.cn>

roles/etcd/tasks/join_etcd-events_member.yml

@@ -34,6 +34,9 @@
   register: etcd_events_member_in_cluster
   changed_when: false
   check_mode: false
+  retries: "{{ etcd_retries }}"
+  delay: "{{ retry_stagger | random + 3 }}"
+  until: etcd_events_member_in_cluster.rc == 0
   tags:
     - facts
   environment: