Add explicity wait:0 to avoid unwanted delay in test

What does this MR do and why?

Noted a delay in group_file_template_spec running this test is caused if the listbox-reset-button isn't actually present - that will cause a 10sec wait in the has_css method slowing our tests down.

This spec runs 4 tests, so adding up to a total of 40sec addition runtime, which can be removed by this change.

How to set up and validate locally

bundle exec rspec ./qa/specs/features/ee/browser_ui/3_create/repository/group_file_template_spec.rb

MR acceptance checklist

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