[BUG] ox-beamer uses ox-latex private functions

[Niall Dooley]

In three separate places (lines 779, 825 and 874) ox-beamer uses
ox-latex private functions namely:

line779: `org-latex--wrap-label'
line 825: `org-latex--insert-compiler'
line 874: `org-latex--format-spec'

I appreciate ox-beamer is a backend backend derived from ox-latex but
isn't this bad practice if these private functions were to change in
future?

Emacs: GNU Emacs 27.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version
3.24.24, cairo version 1.16.0) of 2023-02-23, modified by Debian
Package: Org mode version 9.7-pre (release_9.6.9-818-gac108a)