Can't delete AI Resource that has is_part_of or has_part relationship

[PGijsbers]

Describe the bug
Deleting a dataset when it has an is_part_of and has_part relation to other resources results in an error.
Example error:

ERROR 1451 (23000): Cannot delete or update a parent row: a foreign key constraint fails (`aiod`.`ai_resource_part_link`, CONSTRAINT `ai_resource_part_link_ibfk_2` FOREIGN KEY (`child_identifier`) REFERENCES `ai_resource` (`identifier`))

To Reproduce
TODO

Expected behavior
I expect to be able to delete a dataset even when it has an is_part_of and has_part relation to other resources.
The link should be removed accordingly (cascading deletes should work).

Additional context
n/a