[expr.prim.req] Remove redundant note that repeats what the prior example just said.

Author: zygoloid

source/expressions.tex

@@ -1576,17 +1576,6 @@
 \grammarterm{requires-clause}, and the second
 introduces the \grammarterm{requires-expression}.
 \end{example}
-\begin{note}
-Such requirements can also be written by defining them within
-a concept.
-\begin{codeblock}
-template<typename T>
-  concept C = requires (T x) { x + x; };
-
-template<typename T> requires C<T> 
-  T add(T a, T b) { return a + b; }
-\end{codeblock}
-\end{note}
 
 \pnum
 A \grammarterm{requires-expression} may introduce local parameters using a