Quarantine failing nightly tests

qa/qa/specs/features/browser_ui/3_create/merge_request/merge_merge_request_from_fork_spec.rb

 # frozen_string_literal: true
 module QA
-  context 'Create' do
+  # Failure issue: https://gitlab.com/gitlab-org/quality/nightly/issues/94
+  context 'Create', :quarantine do
     describe 'Merge request creation from fork' do
       it 'user forks a project, submits a merge request and maintainer merges it' do
         Runtime::Browser.visit(:gitlab, Page::Main::Login)

qa/qa/specs/features/browser_ui/3_create/merge_request/squash_merge_request_spec.rb

 # frozen_string_literal: true
 module QA
-  # Failure issue: https://gitlab.com/gitlab-org/quality/staging/issues/31
-  context 'Create' do
+  # Failure issue: https://gitlab.com/gitlab-org/quality/nightly/issues/93
+  context 'Create', :quarantine do
     describe 'Merge request squashing' do
       it 'user squashes commits while merging' do
         Runtime::Browser.visit(:gitlab, Page::Main::Login)