fixup: bump feature-test macro

Author: jensmaurer

source/support.tex

@@ -618,7 +618,7 @@
 #define @\defnlibxname{cpp_lib_constexpr_typeinfo}@                202106L // freestanding, also in \libheader{typeinfo}
 #define @\defnlibxname{cpp_lib_constexpr_utility}@                 201811L // freestanding, also in \libheader{utility}
 #define @\defnlibxname{cpp_lib_constexpr_vector}@                  201907L // also in \libheader{vector}
-#define @\defnlibxname{cpp_lib_constrained_equality}@              202403L // freestanding,
+#define @\defnlibxname{cpp_lib_constrained_equality}@              202411L // freestanding,
   // also in \libheader{utility}, \libheader{tuple}, \libheader{optional}, \libheader{variant}
 #define @\defnlibxname{cpp_lib_containers_ranges}@                 202202L
   // also in \libheader{vector}, \libheader{list}, \libheader{forward_list}, \libheader{map}, \libheader{set}, \libheader{unordered_map}, \libheader{unordered_set},