[entities, view] delete dead code
The auto_unwrap_bw_compat metaclass calls unwrap_adapter_compat, which
was removed in changeset 697a8181ba30 "remove 3.9 bw compat". So this
can't possibly work anymore, meaning we can get rid of it.
from datetime import datetime
for rtype in ('cw_support', 'cw_dont_cross', 'cw_may_cross'):
drop_relation_type(rtype)
add_entity_type('CWSourceSchemaConfig')
if not 'url' in schema['CWSource'].subjrels:
add_attribute('CWSource', 'url')
add_attribute('CWSource', 'parser')
add_attribute('CWSource', 'latest_retrieval')