Scope filter may be broken (KeyError on pk)

[mxsasha]

Logs from an instance on current main:

2021-09-04 13:54:07,369 irrd[1312245]: [irrd.mirroring.mirror_runners_import#ERROR] An exception occurred while attempting a scopefilter status update: 'pk'
Traceback (most recent call last):
  File "/home/irrd/irrd/irrd/mirroring/mirror_runners_import.py", line 311, in run
    status = validator.validate_all_rpsl_objects(self.database_handler)
  File "/home/irrd/irrd/irrd/scopefilter/validators.py", line 141, in validate_all_rpsl_objects
    pks_to_enrich = [obj['pk'] for objs in objs_changed.values() for obj in objs]
  File "/home/irrd/irrd/irrd/scopefilter/validators.py", line 141, in <listcomp>
    pks_to_enrich = [obj['pk'] for objs in objs_changed.values() for obj in objs]
KeyError: 'pk'

Definite new bug in scope filter introduced in #530 because we don't retrieve that column which has not been noticed by the tests. Might be a case of #329. Does not affect 4.1.