Update feature categories for 2020-12-10

The `epic_tracking` category appears to have been added manually; the
other changed categories are currently unused.

config/feature_categories.yml

@@ -43,7 +43,6 @@
 - dynamic_application_security_testing
 - editor_extension
 - epics
-- epic_tracking
 - error_tracking
 - feature_flags
 - five_minute_production_app
@@ -73,7 +72,6 @@
 - live_preview
 - load_testing
 - logging
-- malware_scanning
 - memory
 - merge_trains
 - metrics
@@ -84,7 +82,6 @@
 - package_registry
 - pages
 - pipeline_authoring
-- pki_management
 - planning_analytics
 - product_analytics
 - projects

ee/app/workers/all_queues.yml

@@ -614,7 +614,7 @@
   :idempotent:
   :tags: []
 - :name: todos_destroyer:todos_destroyer_confidential_epic
-  :feature_category: :epic_tracking
+  :feature_category: :epics
   :has_external_dependencies:
   :urgency: :low
   :resource_boundary: :unknown

ee/app/workers/todos_destroyer/confidential_epic_worker.rb

@@ -5,7 +5,7 @@ module TodosDestroyer
     include ApplicationWorker
 
     queue_namespace :todos_destroyer
-    feature_category :epic_tracking
+    feature_category :epics
 
     def perform(epic_id)
       return unless epic_id