Upgrade problem

Preparing to upgrade my small cluster from Mageia 8/Pg 9 to Mageia 9/Pg
15. I'm at the point of running pg_upgrade but have received anerror
message:

/mga8/usr/bin/postgres: error while loading shared libraries:
libssl.so.1.1: cannot open shared object file: No such file or directory
no data was returned by command ""/mga8/usr/bin/postgres" -V"

However:

[root(at)bach lib64]# cd /mga8/usr/lib64
[root(at)bach lib64]# ls -l|grep libssl
-rwxr-xr-x  1 root root      426192 Jul  5 23:07 libssl3.so*
lrwxrwxrwx  1 root root          13 Jun  1 09:35 libssl.so ->
libssl.so.1.1*
-r-xr-xr-x  1 root root      442424 Feb 27  2021 libssl.so.1.0.0*
-rwxr-xr-x  1 root root      666496 Jun  1 09:36 libssl.so.1.1*

Can someone suggest my next move please?

Ta

Graeme Gemmill