ERROR: Can't give out exclusive, lock is in an empty state

[ChuckHend]

During pgml.train(), no error from pgml is logged but then training fails with the error below. Seems like it pgrx is logging that here from here

...
INFO:  Metrics: {"f1": 0.9180161, "precision": 0.91750604, "recall": 0.9205743, "accuracy": 0.9175947, "mcc": 0.90866333, "fit_time": 0.07445792, "score_time": 0.002864594}
INFO:  Deploying model id: 5
ERROR:  Can't give out exclusive, lock is in an empty state

I'm running this on our own postgres 15.3 instance with pgml 2.7.1 installed

I'll work on adding some more detail and steps to reproduce.

[montanalow]

I believe this may be related to #628