[tuple.like] Remove extraneous "std::" qualification.

Author: tkoeppe

source/utilities.tex

@@ -1590,7 +1590,7 @@
 \pnum
 A type \tcode{T} models and satisfies
 the exposition-only concept \exposconcept{tuple-like}
-if \tcode{std::remove_cvref_t<T>} is a specialization of
+if \tcode{remove_cvref_t<T>} is a specialization of
 \tcode{array}, \tcode{pair}, \tcode{tuple}, or \tcode{ranges::subrange}.
 \end{itemdescr}