ox-latex language handling in Org-9.5 vs 9.6

[Max Nikulin]

Hi,

I consider the following as an issue rather close to the discussion in 
the thread
Juan Manuel Macías. Fallback fonts in LaTeX export for non latin 
scripts. Wed, 30 Aug 2023 08:25:53 +0000.
https://list.orgmode.org/878r9t7x7y.fsf@posteo.net

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1042450
elpa-org: #+LANGUAGE: de-de is not working in LaTeX export. Debian Bug 
report logs

I am unsure if the change was intentional.

#+language: de-de
#+latex_header: \usepackage[AUTO]{babel}

is exported to

\usepackage[ngerman]{babel}
% ...
\hypersetup{
% ...
 pdflang={Ngerman}}

by Org-9.5 and as

\usepackage[]{babel}
% ...
\hypersetup{
% ...
 pdflang={De-De}}

by Org-9.6. Similar user expectation should be had in mind during 
planning of further changes.