Run UserRefreshFromReplicaWorker jobs on the replica db by default

This change runs `UserRefreshFromReplicaWorker`
jobs on the replica database by default (if available),
so that all data is read from the replica database
(and not the primary), there by reducing the
number of reads hitting the primary database.

Changelog: performance

app/workers/authorized_project_update/user_refresh_from_replica_worker.rb

@@ -14,19 +14,12 @@ module AuthorizedProjectUpdate
     deduplicate :until_executing, including_scheduled: true
 
     def perform(user_id)
-      if Feature.enabled?(:user_refresh_from_replica_worker_uses_replica_db)
-        use_replica_if_available do
-          user = User.find_by_id(user_id)
-
-          if user && project_authorizations_needs_refresh?(user)
-            enqueue_project_authorizations_refresh(user)
-          end
-        end
-      else
+      use_replica_if_available do
         user = User.find_by_id(user_id)
-        return unless user
 
-        user.refresh_authorized_projects(source: self.class.name)
+        if user && project_authorizations_needs_refresh?(user)
+          enqueue_project_authorizations_refresh(user)
+        end
       end
     end
 

config/feature_flags/development/user_refresh_from_replica_worker_uses_replica_db.yml

----
-name: user_refresh_from_replica_worker_uses_replica_db
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/64276
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/334766
-milestone: '14.1'
-type: development
-group: group::access
-default_enabled: false

spec/workers/authorized_project_update/user_refresh_from_replica_worker_spec.rb

@@ -51,20 +51,5 @@ RSpec.describe AuthorizedProjectUpdate::UserRefreshFromReplicaWorker do
         execute_worker
       end
     end
-
-    context 'when the feature flag `user_refresh_from_replica_worker_uses_replica_db` is disabled' do
-      before do
-        stub_feature_flags(user_refresh_from_replica_worker_uses_replica_db: false)
-      end
-
-      it 'calls Users::RefreshAuthorizedProjectsService' do
-        source = 'AuthorizedProjectUpdate::UserRefreshFromReplicaWorker'
-        expect_next_instance_of(Users::RefreshAuthorizedProjectsService, user, { source: source }) do |service|
-          expect(service).to receive(:execute)
-        end
-
-        execute_worker
-      end
-    end
   end
 end