Re-arrange deployment_platform to avoid cop complainments

app/models/concerns/deployment_platform.rb

 module DeploymentPlatform
   # EE would override this and utilize environment argument
+  # rubocop:disable Gitlab/ModuleWithInstanceVariables
   def deployment_platform(environment: nil)
-    @deployment_platform ||=
-      find_cluster_platform_kubernetes(environment: environment) ||
-      find_kubernetes_service_integration ||
-      build_cluster_and_deployment_platform
+    @deployment_platform ||= {}
+
+    @deployment_platform[environment] ||= find_deployment_platform(environment)
   end
 
   private
 
+  def find_deployment_platform(environment)
+    find_cluster_platform_kubernetes(environment: environment) ||
+      find_kubernetes_service_integration ||
+      build_cluster_and_deployment_platform
+  end
+
   # EE would override this and utilize environment argument
   def find_cluster_platform_kubernetes(environment: nil)
     clusters.enabled.default_environment