Update test and remove from quarantine

What does this MR do and why?

This removes a test from quarantine. It was quarantined because of a bug, which has since been fixed. See #386434 (closed)

There was also a problem with the test, possibly due to a UI change made after the test was quarantined. The test wouldn't pass because of an Ambiguous match error. This fixes that error by using a more specfic selector. Unfortunately, it had to be a CSS selector because the single QA selector gets added to multiple elements.

How to set up and validate locally

From the qa directory, assuming you have a GitLab instance running at http://gdk.test:3000:

bundle exec bin/qa Test::Instance::All http://gdk.test:3000 -- qa/specs/features/ee/browser_ui/10_govern/vulnerability_management_spec.rb

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.