The partition_split test has unstable results, as shown at [1].
I suggest adding "ORDER BY conname" to the two queries shown
to fail there. Better look at other queries in the test for
possible similar problems, too.
regards, tom lane
[1] https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=jackdaw&dt=2024-05-24%2015%3A58%3A17