Merge branch 'vs-ff-subscriptions-plan-cache-key' into 'master'

Add new FF for subscription plan data

See merge request gitlab-org/gitlab!43973

ee/app/services/fetch_subscription_plans_service.rb

@@ -39,6 +39,10 @@ class FetchSubscriptionPlansService
   end
 
   def cache_key
-    "subscription-plans-#{@plan}"
+    if Feature.enabled?(:subscription_plan_cache_key)
+      "subscription-plan-#{@plan}"
+    else
+      "subscription-plans-#{@plan}"
+    end
   end
 end

ee/config/feature_flags/development/subscription_plan_cache_key.yml

+---
+name: subscription_plan_cache_key
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/43973
+rollout_issue_url:
+type: development
+group: group::fulfillment
+default_enabled: false