Promote ui github import and group migration specs to reliable

qa/qa/specs/features/api/1_manage/migration/gitlab_migration_group_spec.rb

 # frozen_string_literal: true
 
 module QA
-  RSpec.describe 'Manage', :requires_admin do
+  RSpec.describe 'Manage', :reliable, :requires_admin do
     describe 'Gitlab migration' do
       let(:import_wait_duration) { { max_duration: 300, sleep_interval: 2 } }
       let(:admin_api_client) { Runtime::API::Client.as_admin }

qa/qa/specs/features/browser_ui/1_manage/project/import_github_repo_spec.rb

 # frozen_string_literal: true
 
 module QA
-  RSpec.describe 'Manage', :github, :requires_admin do
+  RSpec.describe 'Manage', :reliable, :github, :requires_admin do
     describe 'Project import' do
       let(:github_repo) { 'gitlab-qa-github/import-test' }
       let(:api_client) { Runtime::API::Client.as_admin }