Fix Cycle Analytics -> Plan is loading forever

What does this MR do?

We are expecting all received items to have author key but not all of them have it as we can see from this error:

This MR:

• Verifies if the authorkey is present before trying to access it.

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #27622 (closed)