Hitting an assert failure on PG14 in regression tests

[marcocitus]

I seem to repeatedly get the following assert failure when running tests on PG14:

TRAP: FailedAssertion("flags & HASH_STRINGS", File: "dynahash.c", Line: 427, PID: 2936)
postgres: marco contrib_regression [local] SELECT(ExceptionalCondition+0xa5)[0x55a1fcdaa8a9]
postgres: marco contrib_regression [local] SELECT(hash_create+0x307)[0x55a1fcdba45b]
/home/marco/pgsql/14/lib/topn.so(+0x33f0)[0x7fe284c063f0]
/home/marco/pgsql/14/lib/topn.so(topn_union_trans+0xcc)[0x7fe284c06ad7]