Modify API spec to expect a maintainer to be able to create subgroup

spec/requests/api/groups_spec.rb

@@ -803,10 +803,10 @@ describe API::Groups do
           group2.add_maintainer(user1)
         end
 
-        it 'cannot create subgroups' do
+        it 'can create subgroups' do
           post api("/groups", user1), params: { parent_id: group2.id, name: 'foo', path: 'foo' }
 
-          expect(response).to have_gitlab_http_status(403)
+          expect(response).to have_gitlab_http_status(201)
         end
       end
     end

spec/support/shared_contexts/policies/group_policy_shared_context.rb

@@ -19,10 +19,6 @@ RSpec.shared_context 'GroupPolicy context' do
   let(:reporter_permissions) { [:admin_label] }
   let(:developer_permissions) { [:admin_milestone] }
   let(:maintainer_permissions) do
-    %i[
-      create_projects
-      read_cluster create_cluster update_cluster admin_cluster add_cluster
-    ]
     [
       :create_projects,
       :read_cluster,