[repository] when deleting relations of a deleted external entity, we should skip non-crossable relation (closes #1973680)
elses this may lead to things as described in the ticket...
from os.path import join
assert __file__.endswith(join('scripts', 'script3.py')), __file__
assert '__main__' == __name__, __name__
assert ['-vd', '-f', 'FILE.TXT'] == __args__, __args__