[dcl.pre] Fix grammatical error in lambda trailing-return-type (cplusplus#8497)

This seems to be an error in P2996R13.

Author: frederick-vs-ja

source/declarations.tex

@@ -391,7 +391,7 @@
 For a \grammarterm{consteval-block-declaration} $D$,
 the expression $E$ corresponding to $D$ is:
 \begin{codeblock}
-  [] -> void static consteval @\grammarterm{compound-statement}@ ()
+  [] static consteval -> void @\grammarterm{compound-statement}@ ()
 \end{codeblock}
 $E$ shall be a constant expression\iref{expr.const}.
 \begin{note}