[version.syn] Add <numeric> to cpp_lib_freestanding_algorithm macro

The cpp_lib_freestanding_algorithm macro was created by this
paper (LWG Motion 3, P2407R5), but the previous paper (LWG-2, P0543R3)
already added to the freestanding algorithms, so it should also define
this feature test macro.

Author: tkoeppe

source/support.tex

@@ -635,7 +635,7 @@
 #define @\defnlibxname{cpp_lib_format_ranges}@                     202207L // also in \libheader{format}
 #define @\defnlibxname{cpp_lib_formatters}@                        202302L // also in \libheader{stacktrace}, \libheader{thread}
 #define @\defnlibxname{cpp_lib_forward_like}@                      202207L // freestanding, also in \libheader{utility}
-#define @\defnlibxname{cpp_lib_freestanding_algorithm}@            202311L // freestanding, also in \libheader{algorithm}
+#define @\defnlibxname{cpp_lib_freestanding_algorithm}@            202311L // freestanding, also in \libheader{algorithm}, \libheader{numeric}
 #define @\defnlibxname{cpp_lib_freestanding_array}@                202311L // freestanding, also in \libheader{array}
 #define @\defnlibxname{cpp_lib_freestanding_char_traits}@          202306L // freestanding, also in \libheader{string}
 #define @\defnlibxname{cpp_lib_freestanding_charconv}@             202306L // freestanding, also in \libheader{charconv}