[algorithms.requirements] Fix missing \tcode for const (#6936)

Author: eisenwave

source/algorithms.tex

@@ -159,7 +159,7 @@
 \exposconcept{boolean-testable}\iref{concept.booleantestable}.
 The function object \tcode{pred} shall not apply any non-constant function
 through its argument.
-Given a glvalue \tcode{u} of type (possibly const) \tcode{T}
+Given a glvalue \tcode{u} of type (possibly \tcode{const}) \tcode{T}
 that designates the same object as \tcode{*first},
 \tcode{pred(u)} shall be a valid expression
 that is equal to \tcode{pred(*first)}.
@@ -186,9 +186,9 @@
 \exposconcept{boolean-testable}.
 \tcode{binary_pred} shall not apply any non-constant function
 through any of its arguments.
-Given a glvalue \tcode{u} of type (possibly const) \tcode{T1}
+Given a glvalue \tcode{u} of type (possibly \tcode{const}) \tcode{T1}
 that designates the same object as \tcode{*first1}, and
-a glvalue \tcode{v} of type (possibly const) \tcode{T2}
+a glvalue \tcode{v} of type (possibly \tcode{const}) \tcode{T2}
 that designates the same object as \tcode{*first2},
 \tcode{binary_pred(u, *first2)},
 \tcode{binary_pred(*first1, v)}, and