ObsoleteFiles.inc: Automatically generate OpenSSL 3 obsoleted libcompat dirs

Older entries in this file are left alone as hard-coding lib32 as
they're not worth the churn; downstreams will have already moved past
them (in particular, CheriBSD, which adds additional libcompats).

Reviewed by: brooks, jhb, emaste
Differential Revision: https://reviews.freebsd.org/D41181