> > What is the procedure on 13.1 to bring the external (glibc) version > in sync with. the used version in the PostgreSQL database?
If I recall correctly, between versions 10 and 14 you need to use ALTER COLLATION name REFRESH VERSION on every collation where there's a version mismatch. (This can happen with ICU collations since version 10, and with glibc collations since version 13.)
I only know of a small number of changes between glibc versions 2.31 and 2.38 ~ I suspect you already know to look out for glibc 2.28 which was the crazy one. (SLE15 Service Pack 3.) Most databases would be corrupted by that update, and running "refresh version" would simply stop the warnings without fixing the corruption.
