Keep label on issue when moving

What does this MR do?

Keeps the label on an issue when the issue is moved.

Why was this MR needed?

To make sure labels stay on their respective issues.

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Tests added for this feature/bug
• Conform by the code review guidelines
  • Has been reviewed by a Backend maintainer
  • Has been reviewed by a Database specialist
• Conform by the merge request performance guides
• Conform by the style guides
• End-to-end tests pass (package-and-qa manual pipeline job)

What are the relevant issue numbers?

Closes #46098 (closed) - Labels of an issue get deleted when moving the issue