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 ||=
+    @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
 
-  private
-
   # EE would override this and utilize environment argument
   def find_cluster_platform_kubernetes(environment: nil)
     clusters.enabled.default_environment