Stop clearing memoization of `licensed_feature_available` in CORE

After moving features form EE to CORE we forgot to remove these
memoizations; they don't have any effect in CORE.

spec/services/metrics/dashboard/gitlab_alert_embed_service_spec.rb

@@ -10,9 +10,8 @@ RSpec.describe Metrics::Dashboard::GitlabAlertEmbedService do
   let_it_be(:user) { create(:user) }
   let(:alert_id) { alert.id }
 
-  before do
+  before_all do
     project.add_maintainer(user)
-    project.clear_memoization(:licensed_feature_available)
   end
 
   describe '.valid_params?' do

spec/services/projects/alerting/notify_service_spec.rb

@@ -6,8 +6,6 @@ RSpec.describe Projects::Alerting::NotifyService do
   let_it_be(:project, reload: true) { create(:project, :repository) }
 
   before do
-    # We use `let_it_be(:project)` so we make sure to clear caches
-    project.clear_memoization(:licensed_feature_available)
     allow(ProjectServiceWorker).to receive(:perform_async)
   end
 

spec/services/projects/prometheus/alerts/notify_service_spec.rb

@@ -16,11 +16,6 @@ RSpec.describe Projects::Prometheus::Alerts::NotifyService do
 
   let(:subject) { service.execute(token_input) }
 
-  before do
-    # We use `let_it_be(:project)` so we make sure to clear caches
-    project.clear_memoization(:licensed_feature_available)
-  end
-
   context 'with valid payload' do
     let_it_be(:alert_firing) { create(:prometheus_alert, project: project) }
     let_it_be(:alert_resolved) { create(:prometheus_alert, project: project) }