Remove prometheus from managed apps CI artifact parsing

Let's start with Cilium only for now. Prometheus and other applications
that already have existing v1 code should enabled at a later stage

This enables us to rollout cluster_applications_artifact immediately

app/services/clusters/parse_cluster_applications_artifact_service.rb

@@ -5,7 +5,7 @@ module Clusters
     include Gitlab::Utils::StrongMemoize
 
     MAX_ACCEPTABLE_ARTIFACT_SIZE = 5.kilobytes
-    RELEASE_NAMES = %w[prometheus cilium].freeze
+    RELEASE_NAMES = %w[cilium].freeze
 
     def initialize(job, current_user)
       @job = job