Remove typo from factory name

- the typo in this factory name was precluding us from properly
creating dynamic code to remove duplciation.

spec/controllers/admin/clusters/applications_controller_spec.rb

@@ -84,7 +84,7 @@ describe Admin::Clusters::ApplicationsController do
       patch :update, params: params
     end
-    let!(:application) { create(:clusters_applications_cert_managers, :installed, cluster: cluster) }
+    let!(:application) { create(:clusters_applications_cert_manager, :installed, cluster: cluster) }
     let(:application_name) { application.name }
     let(:params) { { application: application_name, id: cluster.id, email: "new-email@example.com" } }

spec/controllers/groups/clusters/applications_controller_spec.rb

@@ -91,7 +91,7 @@ describe Groups::Clusters::ApplicationsController do
       patch :update, params: params.merge(group_id: group)
     end
-    let!(:application) { create(:clusters_applications_cert_managers, :installed, cluster: cluster) }
+    let!(:application) { create(:clusters_applications_cert_manager, :installed, cluster: cluster) }
     let(:application_name) { application.name }
     let(:params) { { application: application_name, id: cluster.id, email: "new-email@example.com" } }

spec/factories/clusters/applications/helm.rb

@@ -60,7 +60,7 @@ FactoryBot.define do
       cluster factory: %i(cluster with_installed_helm provided_by_gcp)
     end
-    factory :clusters_applications_cert_managers, class: Clusters::Applications::CertManager do
+    factory :clusters_applications_cert_manager, class: Clusters::Applications::CertManager do
       email 'admin@example.com'
       cluster factory: %i(cluster with_installed_helm provided_by_gcp)
     end

spec/lib/gitlab/usage_data_spec.rb

@@ -24,7 +24,7 @@ describe Gitlab::UsageData do
       create(:cluster, :group, :disabled)
       create(:clusters_applications_helm, :installed, cluster: gcp_cluster)
       create(:clusters_applications_ingress, :installed, cluster: gcp_cluster)
-      create(:clusters_applications_cert_managers, :installed, cluster: gcp_cluster)
+      create(:clusters_applications_cert_manager, :installed, cluster: gcp_cluster)
       create(:clusters_applications_prometheus, :installed, cluster: gcp_cluster)
       create(:clusters_applications_runner, :installed, cluster: gcp_cluster)
       create(:clusters_applications_knative, :installed, cluster: gcp_cluster)

spec/models/clusters/applications/cert_manager_spec.rb

@@ -3,11 +3,11 @@
 require 'rails_helper'
 describe Clusters::Applications::CertManager do
-  let(:cert_manager) { create(:clusters_applications_cert_managers) }
-  include_examples 'cluster application core specs', :clusters_applications_cert_managers
-  include_examples 'cluster application status specs', :clusters_applications_cert_managers
-  include_examples 'cluster application version specs', :clusters_applications_cert_managers
+  let(:cert_manager) { create(:clusters_applications_cert_manager) }
+  include_examples 'cluster application core specs', :clusters_applications_cert_manager
+  include_examples 'cluster application status specs', :clusters_applications_cert_manager
+  include_examples 'cluster application version specs', :clusters_applications_cert_manager
   include_examples 'cluster application initial status specs'
   describe '#can_uninstall?' do
@@ -72,7 +72,7 @@ describe Clusters::Applications::CertManager do
     end
     context 'application failed to install previously' do
-      let(:cert_manager) { create(:clusters_applications_cert_managers, :errored, version: '0.0.1') }
+      let(:cert_manager) { create(:clusters_applications_cert_manager, :errored, version: '0.0.1') }
       it 'is initialized with the locked version' do
         expect(subject.version).to eq('v0.5.2')

spec/models/clusters/cluster_spec.rb

@@ -496,7 +496,7 @@ describe Clusters::Cluster, :use_clean_rails_memory_store_caching do
     context 'when applications are created' do
       let!(:helm) { create(:clusters_applications_helm, cluster: cluster) }
       let!(:ingress) { create(:clusters_applications_ingress, cluster: cluster) }
-      let!(:cert_manager) { create(:clusters_applications_cert_managers, cluster: cluster) }
+      let!(:cert_manager) { create(:clusters_applications_cert_manager, cluster: cluster) }
       let!(:prometheus) { create(:clusters_applications_prometheus, cluster: cluster) }
       let!(:runner) { create(:clusters_applications_runner, cluster: cluster) }
       let!(:jupyter) { create(:clusters_applications_jupyter, cluster: cluster) }