Add ci_server_url to variable list

What does this MR do and why?

Adds CI_SERVER_URL variable to list of vars passed through to test container

MR acceptance checklist

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

• Commits include Changelog: trailer
• I have evaluated the MR acceptance checklist for this MR.