[lex.ext] Remove \grammarterm for consistency

Author: Andreas-Krug

source/lex.tex

@@ -2254,7 +2254,7 @@
 Otherwise, \placeholder{S} shall contain a raw literal operator
 or a numeric literal operator template\iref{over.literal} but not both.
 If \placeholder{S} contains a raw literal operator,
-the \grammarterm{literal} \placeholder{L} is treated as a call of the form
+the literal \placeholder{L} is treated as a call of the form
 \begin{codeblock}
 operator ""@\placeholder{X}@("@\placeholder{f}@")
 \end{codeblock}