Add E2E test for fix vulnerability workflow

What does this MR do and why?

This MR introduces a new E2E test to validate fix a vulnerability workflow as described in https://gitlab.com/gitlab-org/quality/team-tasks/-/issues/1222#note_938951421

How to set up and validate locally

Run the test against GDK

GITLAB_QA_ACCESS_TOKEN=XXXXX GITLAB_PASSWORD="XXXXXX" QA_DEBUG=true CHROME_HEADLESS=false bundle exec bin/qa Test::Instance::All http://192.168.1.105:3000 ./qa/specs/features/ee/browser_ui/13_secure/fix_vulnerability_workflow_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.