Enable Runner ancestor scopes

app/models/ci/runner.rb

@@ -81,14 +81,7 @@ module Ci
 
     scope :belonging_to_group, -> (group_id, include_ancestors: false) {
       groups = ::Group.where(id: group_id)
-
-      if include_ancestors
-        groups = if Feature.enabled?(:linear_runner_ancestor_scopes, default_enabled: :yaml)
-                   groups.self_and_ancestors
-                 else
-                   Gitlab::ObjectHierarchy.new(groups).base_and_ancestors
-                 end
-      end
+      groups = groups.self_and_ancestors if include_ancestors
 
       joins(:runner_namespaces)
         .where(ci_runner_namespaces: { namespace_id: groups })
@@ -109,14 +102,9 @@ module Ci
 
     scope :belonging_to_parent_group_of_project, -> (project_id) {
       project_groups = ::Group.joins(:projects).where(projects: { id: project_id })
-      hierarchy_groups = if Feature.enabled?(:linear_runner_ancestor_scopes, default_enabled: :yaml)
-                           project_groups.self_and_ancestors.as_ids
-                         else
-                           Gitlab::ObjectHierarchy.new(project_groups).base_and_ancestors
-                         end
 
       joins(:groups)
-        .where(namespaces: { id: hierarchy_groups })
+        .where(namespaces: { id: project_groups.self_and_ancestors.as_ids })
         .allow_cross_joins_across_databases(url: 'https://gitlab.com/gitlab-org/gitlab/-/issues/336433')
     }
 

config/feature_flags/development/linear_runner_ancestor_scopes.yml

----
-name: linear_runner_ancestor_scopes
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/70385
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/341114
-milestone: '14.6'
-type: development
-group: group::access
-default_enabled: false

spec/models/ci/runner_spec.rb

@@ -204,7 +204,6 @@ RSpec.describe Ci::Runner do
   end
 
   describe '.belonging_to_parent_group_of_project' do
-    shared_examples 'returns parent group project runners' do
     let(:project) { create(:project, group: group) }
     let(:group) { create(:group) }
     let(:runner) { create(:ci_runner, :group, groups: [group]) }
@@ -228,17 +227,6 @@ RSpec.describe Ci::Runner do
     end
   end
 
-    it_behaves_like 'returns parent group project runners'
-
-    context 'when feature flag :linear_runner_ancestor_scopes is disabled' do
-      before do
-        stub_feature_flags(linear_runner_ancestor_scopes: false)
-      end
-
-      it_behaves_like 'returns parent group project runners'
-    end
-  end
-
   describe '.owned_or_instance_wide' do
     it 'returns a globally shared, a project specific and a group specific runner' do
       # group specific