fixup: use \libconcept

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

Author: dietmarkuehl

source/exec.tex

@@ -6410,7 +6410,7 @@
 \begin{itemdescr}
 \pnum
 \returns
-If \tcode{same_as<inline_scheduler, scheduler_type>} is \tcode{true}
+If \tcode{@\libconcept{same_as}@<inline_scheduler, scheduler_type>} is \tcode{true}
 returns \tcode{as_awaitable(\brk{}std::forward<Sender>(sndr), *this)};
 otherwise returns
 \tcode{as_awaitable(affine_on(\brk{}std::forward<Sender>(sndr), \exposid{SCHED}(*this)), *this)}.