Remove serverless feature category

This was removed in
https://gitlab.com/gitlab-com/www-gitlab-com/-/merge_requests/86018. As
that MR notes usage was very low, having this unowned is probably fine.

The other categories changed here (GDK, Scalability, Horse, etc.) do not
own any endpoints in the Rails app.

app/controllers/admin/serverless/domains_controller.rb

@@ -4,7 +4,7 @@ class Admin::Serverless::DomainsController < Admin::ApplicationController
   before_action :check_feature_flag
   before_action :domain, only: [:update, :verify, :destroy]
 
-  feature_category :serverless
+  feature_category :not_owned
 
   def index
     @domain = PagesDomain.instance_serverless.first_or_initialize

app/controllers/projects/serverless/functions_controller.rb

@@ -5,7 +5,7 @@ module Projects
     class FunctionsController < Projects::ApplicationController
       before_action :authorize_read_cluster!
 
-      feature_category :serverless
+      feature_category :not_owned
 
       def index
         respond_to do |format|

config/feature_categories.yml

@@ -33,6 +33,7 @@
 - continuous_integration_scaling
 - database
 - dataops
+- delivery
 - delivery_management
 - dependency_firewall
 - dependency_proxy
@@ -53,16 +54,15 @@
 - five_minute_production_app
 - foundations
 - fuzz_testing
-- gdk
 - geo_replication
 - git_lfs
 - gitaly
 - gitlab_docs
 - global_search
 - helm_chart_registry
+- horse
 - importers
 - incident_management
-- infrastructure
 - infrastructure_as_code
 - insider_threat
 - integrations
@@ -103,12 +103,12 @@
 - roadmaps
 - runbooks
 - runner
+- scalability
 - secret_detection
 - secrets_management
 - security_benchmarking
 - security_orchestration
 - self_monitoring
-- serverless
 - service_desk
 - service_ping
 - sharding