[BE] Remove FF and ensure rspec is passing
The GraphQL FF was disabled for existing RSpecs as the the migration is WIP. Once the migration is completed, we should re-enable the FF and make sure the tests are passing. If no update specs where needed. Removing the stub `mr_security_widget_graphql`: - `ee/spec/features/merge_request/user_sees_security_widget_spec.rb` - `qa/qa/specs/features/ee/browser_ui/18_security_risk_management/dismissed_vulnerabilities_in_security_widget_spec.rb` - `qa/qa/specs/features/ee/browser_ui/18_security_risk_management/vulnerability_management_spec.rb`
issue