Problem/Motivation
\Drupal\migrate\Annotation\MigrateDestination contains a derivative property. A derivative is a plugin and not the class that provides derivative plugin definitions (they have long since been renamed to derivers, and on top of that no other annotation in core specifies that a deriver property can be set.
Proposed resolution
Remove the property entirely for consistency with the rest of Drupal core.
Remaining tasks
None.
User interface changes
None.
API changes
None.