LocksTest fails in rawhide

[mizdebsk]

Current master branch does not build in mock chroot due to LocksTest failure:

ERROR: test_session_lock_exception_propagation (test.locks_test.LocksTest)
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Traceback (most recent call last):
  File "/builddir/build/BUILD/koschei-2.4.0/test/locks_test.py", line 61, in test_session_lock_exception_propagation
    with pg_session_lock(self.s2.db, LOCK_REPO_RESOLVER, 1, block=False):
  File "/usr/lib64/python3.7/contextlib.py", line 112, in __enter__
    return next(self.gen)
  File "/builddir/build/BUILD/koschei-2.4.0/koschei/locks.py", line 101, in pg_session_lock
    pg_lock(db, namespace, key, block=block, shared=shared)
  File "/builddir/build/BUILD/koschei-2.4.0/koschei/locks.py", line 66, in pg_lock
    raise Locked()
koschei.locks.Locked