Remove project_statistics_sync feature flag

The feature flag has been enabled for a while, we can remove it

Changelog: other

app/controllers/repositories/git_http_controller.rb

@@ -84,11 +84,7 @@ module Repositories
 
       return if Feature.enabled?(:disable_git_http_fetch_writes)
 
-      if Feature.enabled?(:project_statistics_sync, project, default_enabled: true)
-        Projects::FetchStatisticsIncrementService.new(project).execute
-      else
-        ProjectDailyStatisticsWorker.perform_async(project.id) # rubocop:disable CodeReuse/Worker
-      end
+      Projects::FetchStatisticsIncrementService.new(project).execute
     end
 
     def access

config/feature_flags/development/project_statistics_sync.yml

----
-name: project_statistics_sync
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/29636
-rollout_issue_url: 
-milestone: '12.10'
-type: development
-group: group::source code
-default_enabled: true

spec/controllers/repositories/git_http_controller_spec.rb

@@ -34,18 +34,6 @@ RSpec.describe Repositories::GitHttpController do
           end
         end
 
-        context 'when project_statistics_sync feature flag is disabled' do
-          before do
-            stub_feature_flags(project_statistics_sync: false, disable_git_http_fetch_writes: false)
-          end
-
-          it 'updates project statistics async for projects' do
-            expect(ProjectDailyStatisticsWorker).to receive(:perform_async)
-
-            send_request
-          end
-        end
-
         it 'updates project statistics sync for projects' do
           stub_feature_flags(disable_git_http_fetch_writes: false)