[meta.unary.prop] Fix typo 'remove_all_extents<T>' which should say

'remove_all_extents_t<T>', introduced editorially in commit 7997487.

Fixes #1644.

Author: zygoloid

source/utilities.tex

@@ -16055,7 +16055,7 @@
   is well-formed
   when treated as an unevaluated operand (Clause \ref{expr}),
   where \tcode{U} is
-  \tcode{remove_all_extents<T>}. &
+  \tcode{remove_all_extents_t<T>}. &
   \tcode{T} shall be a complete type, \cv{}~\tcode{void},
   or an array of unknown bound. \\ \rowsep