Comment 6 for bug 1937294

As a specific example, what we're doing to create call numbers, copies, and assign copy locations gives different results on Pg11+ vs. Pg9.6 and Pg10:

http://irc.evergreen-ils.org/evergreen/2021-11-10#i_495073

When I asked about it in #postgresql, I was told that we need a more deterministic way of inserting our test data that doesn't rely on undefined behavior.