fixup: remove extraneous space after ==

Co-authored-by: Jan Schultke <[email protected]>

Author: dietmarkuehl

source/exec.tex

@@ -5896,7 +5896,7 @@
 template<class Sch>
   requires (!@\libconcept{same_as}@<task_scheduler, Sch>)
         && @\libconcept{scheduler}@<Sch>
-bool operator== (const task_scheduler& lhs, const Sch& rhs) noexcept;
+bool operator==(const task_scheduler& lhs, const Sch& rhs) noexcept;
 \end{itemdecl}
 
 \begin{itemdescr}