Only sticky flash notifications should have top value

What does this MR do?

We should only adjust top value of the Flash notifications if they are sticky.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Closes #32063 (closed)