Use CS_IGNORE_STATUSES to ignore non-actionable CS findings

What does this MR do?

Leverage the new CS_IGNORE_STATUSES variable to configure container scanning to ignore non-actionable findings and skip them in the generated security report. Reporting these findings would only lead to the creation of SLA Exception Requests which is a waste of time for our development and security teams.

This policy will also be documented soon in the handbook.

What are the relevant issue numbers?

Does this MR meet the acceptance criteria?

• Changelog trailer added
• Documentation created/updated for GitLab EE, if necessary
• Documentation created/updated for this project, if necessary
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Job definition updated, if necessary
  • Auto-DevOps template
  • Job definition example
  • CI Templates
• Conforms to the code review guidelines
• Conforms to the Go guidelines
• Security reports checked/validated by reviewer