UTF-8 characters in filenames with Lilypond 2.23

[David F.]

System: Intel-based macOS

I make extensive use of UTF-8 characters in the filenames of my Lilypond files. 
 This works in Lilypond up through version 2.22.  But Lilypond 2.23 cannot 
handle UTF-8 characters in filenames.

Filename: tést.ly
====
\version "2.22"

{ c' }
====

Under v2.22, this file complies without problem.  With 2.23 (including the just 
release 2.23.9) I get the following error:

Starting lilypond 2.23.9 [tést.ly]...
warning: cannot find file: `/Users/david/Projects/Lily Scratch/te??st.ly'
fatal error: failed files: "/Users/david/Projects/Lily Scratch/te??st.ly"
Exited with return code 1.

I thought that this problem had already been reported, but I can’t find any 
mention of it now.  So I’m reporting it.

David F.