[temp.deduct.general] Replace "nontype template argument" with "constant template argument"

Author: eisenwave

source/templates.tex

@@ -7921,7 +7921,7 @@
 The substitution occurs in all types and expressions that are used
 in the deduction substitution loci.
 The expressions include not only
-constant expressions such as those that appear in array bounds or as nontype
+constant expressions such as those that appear in array bounds or as constant
 template arguments but also general expressions (i.e., non-constant expressions)
 inside \tcode{sizeof}, \keyword{decltype}, and other contexts that allow non-constant
 expressions. The substitution proceeds in lexical order and stops when