Resolve flaky tests in spec/frontend/vue_merge_request_widget/mr_widget_options_spec.js

Resolve flaky tests in spec/frontend/vue_merge_request_widget/mr_widget_options_spec.js.

How to reproduce

• yarn jest --no-cache spec/frontend/vue_merge_request_widget/mr_widget_options_spec.js
• If it does not fail, try to run it several times.