Fix release version name

Author: seunghun1ee

etc/kayobe/kolla.yml

@@ -141,11 +141,11 @@ kolla_sources:
   prometheus-v2-server:
     type: git
     location: https://github.com/prometheus/prometheus.git
-    reference: 2.54.1
+    reference: v2.54.1
   prometheus-memcached-exporter:
     type: git
     location: https://github.com/prometheus/memcached_exporter.git
-    reference: 0.14.4
+    reference: v0.14.4
 
 ###############################################################################
 # Kolla image build configuration.