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

**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