Fix ability to edit diff notes multiple times

What does this MR do?

Fixes a regression where editing a diff note again after editing it once is not possible. This regression was introduced by !10760 (merged) as a part of %9.2 release.

Does this MR meet the acceptance criteria?

• [ ] Changelog entry added, if necessary
• [ ] 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 #32425 (closed)