Use linear version GroupsWithTemplatesFinder#extended_group_search

In this commit we're removing the ff
`linear_groups_template_finder_extended_group_search_ancestors_scopes`
and enabling the linear version of
`GroupsWithTemplatesFinder#extended_group_search`.

Changelog: changed
EE: true

config/feature_flags/development/linear_groups_template_finder_extended_group_search_ancestors_scopes.yml

----
-name: linear_groups_template_finder_extended_group_search_ancestors_scopes
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/74599
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/345786
-milestone: '14.6'
-type: development
-group: group::access
-default_enabled: false

ee/app/finders/groups_with_templates_finder.rb

@@ -18,16 +18,11 @@ def execute
   attr_reader :group_id
   def extended_group_search
-    # We're adding an extra query that will be removed once we remove the feature flag in https://gitlab.com/gitlab-org/gitlab/-/issues/339439
-    groups = if Feature.enabled?(:linear_groups_template_finder_extended_group_search_ancestors_scopes, current_group, default_enabled: :yaml)
-               Group.with_project_templates.self_and_ancestors
-             else
-               Gitlab::ObjectHierarchy
-                 .new(Group.with_project_templates)
-                 .base_and_ancestors
-             end
-
-    groups.with_feature_available_in_plan(:group_project_templates).self_and_descendants
+    Group
+      .with_project_templates
+      .self_and_ancestors
+      .with_feature_available_in_plan(:group_project_templates)
+      .self_and_descendants
   end
   def simple_group_search(groups)
@@ -36,9 +31,4 @@ def simple_group_search(groups)
     groups.with_project_templates
   end
-
-  # This method will be removed https://gitlab.com/gitlab-org/gitlab/-/issues/339439
-  def current_group
-    Group.find_by(id: group_id) # rubocop:disable CodeReuse/ActiveRecord
-  end
 end

ee/spec/finders/groups_with_templates_finder_spec.rb

@@ -26,38 +26,57 @@
     create(:gitlab_subscription, :premium, namespace: group_2)
   end
-  shared_examples 'group template finder examples' do
-    describe 'without group id' do
-      it 'returns all groups' do
-        expect(described_class.new.execute).to contain_exactly(group_1, group_2, group_3)
+  describe 'without group id' do
+    it 'returns all groups' do
+      expect(described_class.new.execute).to contain_exactly(group_1, group_2, group_3)
+    end
+
+    context 'when namespace checked' do
+      before do
+        allow(Gitlab::CurrentSettings).to receive(:should_check_namespace_plan?) { true }
+      end
+
+      it 'returns groups on ultimate/premium plan' do
+        expect(described_class.new.execute).to contain_exactly(group_1, group_2)
       end
-      context 'when namespace checked' do
+      context 'with subgroup with template' do
         before do
-          allow(Gitlab::CurrentSettings).to receive(:should_check_namespace_plan?) { true }
+          subgroup_4.update!(custom_project_templates_group_id: subgroup_5.id)
+          create(:project, namespace: subgroup_5)
         end
         it 'returns groups on ultimate/premium plan' do
-          expect(described_class.new.execute).to contain_exactly(group_1, group_2)
+          expect(described_class.new.execute).to contain_exactly(group_1, group_2, subgroup_4)
         end
-        context 'with subgroup with template' do
-          before do
-            subgroup_4.update!(custom_project_templates_group_id: subgroup_5.id)
-            create(:project, namespace: subgroup_5)
-          end
-          it 'returns groups on ultimate/premium plan' do
-            expect(described_class.new.execute).to contain_exactly(group_1, group_2, subgroup_4)
-          end
-        end
+      end
+    end
+  end
+  describe 'with group id' do
+    it 'returns given group with it descendants' do
+      expect(described_class.new(group_1.id).execute).to contain_exactly(group_1)
+    end
+    context 'with subgroup with template' do
+      before do
+        subgroup_4.update!(custom_project_templates_group_id: subgroup_5.id)
+        create(:project, namespace: subgroup_5)
       end
-    end
-    describe 'with group id' do
-      it 'returns given group with it descendants' do
+      it 'returns only chosen group' do
         expect(described_class.new(group_1.id).execute).to contain_exactly(group_1)
       end
+    end
+
+    context 'when namespace checked' do
+      before do
+        allow(Gitlab::CurrentSettings).to receive(:should_check_namespace_plan?) { true }
+      end
+
+      it 'does not return the group' do
+        expect(described_class.new(group_3.id).execute).to be_empty
+      end
       context 'with subgroup with template' do
         before do
@@ -68,42 +87,11 @@
         it 'returns only chosen group' do
           expect(described_class.new(group_1.id).execute).to contain_exactly(group_1)
         end
-      end
-
-      context 'when namespace checked' do
-        before do
-          allow(Gitlab::CurrentSettings).to receive(:should_check_namespace_plan?) { true }
-        end
-        it 'does not return the group' do
-          expect(described_class.new(group_3.id).execute).to be_empty
-        end
-
-        context 'with subgroup with template' do
-          before do
-            subgroup_4.update!(custom_project_templates_group_id: subgroup_5.id)
-            create(:project, namespace: subgroup_5)
-          end
-
-          it 'returns only chosen group' do
-            expect(described_class.new(group_1.id).execute).to contain_exactly(group_1)
-          end
-
-          it 'returns only chosen subgroup' do
-            expect(described_class.new(subgroup_4.id).execute).to contain_exactly(group_1, subgroup_4)
-          end
+        it 'returns only chosen subgroup' do
+          expect(described_class.new(subgroup_4.id).execute).to contain_exactly(group_1, subgroup_4)
         end
       end
     end
   end
-
-  it_behaves_like 'group template finder examples'
-
-  context 'when feature flag :linear_groups_template_finder_extended_group_search_ancestors_scopes is disabled' do
-    before do
-      stub_feature_flags(linear_groups_template_finder_extended_group_search_ancestors_scopes: false)
-    end
-
-    it_behaves_like 'group template finder examples'
-  end
 end