Quoting quoted material fails
Reported by Mats Bengtsson on bug-lilypond (https://lists.gnu.org/archive/html/bug-lilypond/2021-08/msg00002.html).
Quoting music that itself contains quoted material fails.
\version "2.23.4"
A = \fixed c' {c4 d e f | g f e d | c1 }
\addQuote "A" {\A }
B = \fixed c' {\quoteDuring "A" s1 | g1 | \quoteDuring "A" s1 }
\addQuote "B" {\B}
% The first measure that attempts to quote quoted material is empty:
C = \fixed c' {\quoteDuring "B" s1*2 | e1 }
\score{
<<
\new Staff \A
\new Staff \B
\new Staff \C
>>
}
CC @eble