Enable optimized_issuable_label_filter FF

Enable optimized_issuable_label_filter feature flag by default.

app/models/concerns/optimized_issuable_label_filter.rb

@@ -13,7 +13,7 @@ module OptimizedIssuableLabelFilter
   def by_label(items)
     return items unless params.labels?
 
-    return super if Feature.disabled?(:optimized_issuable_label_filter)
+    return super if Feature.disabled?(:optimized_issuable_label_filter, default_enabled: :yaml)
 
     target_model = items.model
 
@@ -29,7 +29,7 @@ module OptimizedIssuableLabelFilter
   # Taken from IssuableFinder
   def count_by_state
     return super if root_namespace.nil?
-    return super if Feature.disabled?(:optimized_issuable_label_filter)
+    return super if Feature.disabled?(:optimized_issuable_label_filter, default_enabled: :yaml)
 
     count_params = params.merge(state: nil, sort: nil, force_cte: true)
     finder = self.class.new(current_user, count_params)

changelogs/unreleased/259719-rollout-optimized-labels-ff.yml

+---
+title: Improve the performance of merge request and issue search by label(s)
+merge_request: 52495
+author:
+type: performance

config/feature_flags/development/optimized_issuable_label_filter.yml

@@ -5,4 +5,4 @@ rollout_issue_url:
 milestone: '13.4'
 type: development
 group: group::analytics
-default_enabled: false
+default_enabled: true