Rename prometheus-v2-server to prometheus-server

With Kolla bumping Promtheus to v3, the v2 name has been dropped.
Updates our tooling to reflect that.

Author: MoteHue

etc/kayobe/pulp.yml

@@ -526,7 +526,7 @@ stackhpc_pulp_images_kolla:
   - prometheus-mysqld-exporter
   - prometheus-node-exporter
   - prometheus-openstack-exporter
-  - prometheus-v2-server
+  - prometheus-server
   - proxysql
   - rabbitmq
   - redis

tools/kolla-images.py

@@ -72,7 +72,7 @@
     "ovn-sb-db-server": [
         "ovn_sb_db",
     ],
-    "prometheus-v2-server": [
+    "prometheus-server": [
         "prometheus_server",
     ],
 }