devel/m17n-lib: upgrade to 1.8.5

PR: 287345
Approved by: maintainer’s time-out

Last announcement at
https://lists.nongnu.org/archive/html/m17n-list/2025-02/msg00003.html

Also don’t disable NLS by default.

Remark: it seems that japanese/anthy (legacy) could be replaced by japanese/anthy-unicode (prefered).

Reported by: thierry