Remove `ci_bulk_insert_on_create` feature flag

This removes a feature flag
that is already `default_enabled: true`

app/services/ci/retry_build_service.rb

@@ -58,7 +58,7 @@ module Ci
       build = project.builds.new(attributes)
       build.assign_attributes(::Gitlab::Ci::Pipeline::Seed::Build.environment_attributes_for(build))
       build.retried = false
-      BulkInsertableAssociations.with_bulk_insert(enabled: ::Gitlab::Ci::Features.bulk_insert_on_create?(project)) do
+      BulkInsertableAssociations.with_bulk_insert do
         build.save!
       end
       build

config/feature_flags/development/ci_bulk_insert_on_create.yml

----
-name: ci_bulk_insert_on_create
-introduced_by_url: 
-rollout_issue_url: 
-group: 
-type: development
-default_enabled: true

lib/gitlab/ci/features.rb

@@ -35,10 +35,6 @@ module Gitlab
         ::Feature.enabled?(:ci_raise_job_rules_without_workflow_rules_warning, default_enabled: true)
       end
 
-      def self.bulk_insert_on_create?(project)
-        ::Feature.enabled?(:ci_bulk_insert_on_create, project, default_enabled: true)
-      end
-
       # NOTE: The feature flag `disallow_to_create_merge_request_pipelines_in_target_project`
       # is a safe switch to disable the feature for a parituclar project when something went wrong,
       # therefore it's not supposed to be enabled by default.

lib/gitlab/ci/pipeline/chain/create.rb

@@ -8,7 +8,7 @@ module Gitlab
           include Chain::Helpers
 
           def perform!
-            BulkInsertableAssociations.with_bulk_insert(enabled: ::Gitlab::Ci::Features.bulk_insert_on_create?(project)) do
+            BulkInsertableAssociations.with_bulk_insert do
               pipeline.save!
             end
           rescue ActiveRecord::RecordInvalid => e