Failure to compile

[José Matos]

I get this at current git:

/home/jamatos/lyx/lyx/src/insets/InsetBibtex.cpp: In member function
‘virtual void lyx::InsetBibtex::docbook(lyx::XMLStream&, const
lyx::OutputParams&) const’:
/home/jamatos/lyx/lyx/src/insets/InsetBibtex.cpp:1223:70: error: ‘class
std::set<std::__cxx11::basic_string<char> >’ has no member named
‘contains’
 1223 |                                         if
(alreadyOutputDocBookTags.contains(docbookTag)) {
      |                                                               
^~~~~~~~

@Thibaut isn't the contains method C++20?

FWIW I am using gcc 14 (pre-release).

Best regards,
-- 
José Abílio