Update Load Performance Testing k6 version to 0.27.0

What does this MR do?

Updates the k6 version to 0.27.0 for Load Performance Testing. Brings in more flexibility in tests and the ability to run multiple scenarios for users.

Screenshots

Example MR - https://gitlab.com/gitlab-org/quality/mr-performance-tests/-/merge_requests/1

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content