[support.start.term] Update to refer to C23 7.24.5

... due to new sections added after WG14 N3220

Author: frederick-vs-ja

source/support.tex

@@ -2328,7 +2328,7 @@
 when the functions registered with \tcode{at_quick_exit} are.
 \end{itemdescr}
 
-\xrefc{7.24.4}
+\xrefc{7.24.5}
 
 \rSec1[support.dynamic]{Dynamic memory management}