Remove usage_data_diff_searches feature flag

Changelog: removed

app/assets/javascripts/diffs/components/app.vue

@@ -534,10 +534,8 @@ export default {
           if (delta >= 0 && delta < 1000) {
             this.disableVirtualScroller();
 
-            if (window.gon?.features?.usageDataDiffSearches) {
-              api.trackRedisHllUserEvent('i_code_review_user_searches_diff');
-              api.trackRedisCounterEvent('diff_searches');
-            }
+            api.trackRedisHllUserEvent('i_code_review_user_searches_diff');
+            api.trackRedisCounterEvent('diff_searches');
           }
         }
       });

app/controllers/projects/merge_requests_controller.rb

@@ -47,7 +47,6 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
     # Usage data feature flags
     push_frontend_feature_flag(:users_expanding_widgets_usage_data, project, default_enabled: :yaml)
     push_frontend_feature_flag(:diff_settings_usage_data, default_enabled: :yaml)
-    push_frontend_feature_flag(:usage_data_diff_searches, project, default_enabled: :yaml)
   end
 
   before_action do

config/feature_flags/development/usage_data_diff_searches.yml

----
-name: usage_data_diff_searches
-introduced_by_url:
-rollout_issue_url:
-milestone: '14.2'
-type: development
-group: group::code review
-default_enabled: true

lib/gitlab/usage_data_counters/known_events/code_review_events.yml

@@ -246,7 +246,6 @@
   redis_slot: code_review
   category: code_review
   aggregation: weekly
-  feature_flag: usage_data_diff_searches
 - name: i_code_review_total_suggestions_applied
   redis_slot: code_review
   category: code_review