Fix build with libc++22: Boost operator[] proxy breaks template argument
deduction in LocaleBasedSorting.
Index: src/screens/sel_items_adder.cpp
--- src/screens/sel_items_adder.cpp.orig
+++ src/screens/sel_items_adder.cpp
@@ -254,7 +254,9 @@ void SelectedItemsAdder::populatePlaylistSelector(Base
 			));
 		};
 		std::sort(m_playlist_selector.beginV()+begin, m_playlist_selector.endV(),
-			LocaleBasedSorting(std::locale(), Config.ignore_leading_the));
+			[cmp = LocaleBasedSorting(std::locale(), Config.ignore_leading_the)]
+			(const Entry &a, const Entry &b) { return cmp(a, b); });
+
 		if (begin < m_playlist_selector.size())
 			m_playlist_selector.addSeparator();
 	}
