Release Jira Service Management feature

What does this MR do and why?

Releasees the Jira Service Management feature by removing the feature flag.

• #460663 (closed)
• #467117 (closed)

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Related to #467117 (closed)