Fix some specs using the old ContainerImage const

spec/features/container_registry_spec.rb

@@ -39,7 +39,7 @@ describe "Container Registry" do
     end
     it do
-      expect_any_instance_of(ContainerImage).to receive(:delete_tags).and_return(true)
+      expect_any_instance_of(ContainerRepository).to receive(:delete_tags).and_return(true)
       click_on 'Remove image'
     end

spec/services/projects/destroy_service_spec.rb

@@ -100,7 +100,7 @@ describe Projects::DestroyService, services: true do
     context 'images deletion succeeds' do
       it do
-        expect_any_instance_of(ContainerImage).to receive(:delete_tags).and_return(true)
+        expect_any_instance_of(ContainerRepository).to receive(:delete_tags).and_return(true)
         destroy_project(project, user, {})
       end
@@ -108,7 +108,7 @@ describe Projects::DestroyService, services: true do
     context 'images deletion fails' do
       before do
-        expect_any_instance_of(ContainerImage).to receive(:delete_tags).and_return(false)
+        expect_any_instance_of(ContainerRepository).to receive(:delete_tags).and_return(false)
       end
       subject { destroy_project(project, user, {}) }