[task.promise] Move period to end of sentence

Author: Andreas-Krug

source/exec.tex

@@ -7683,7 +7683,7 @@
 \item \tcode{env.query(get_stop_token)} returns \exposid{token}.
 \item For any other query \tcode{q} and arguments \tcode{a...} a
 call to \tcode{env.query(q, a...)} returns
-\tcode{\exposid{STATE}(*this).} \tcode{environment.query(q, a...)} if this expression
+\tcode{\exposid{STATE}(*this)}. \tcode{environment.query(q, a...)} if this expression
 is well-formed and \tcode{forwarding_query(q)} is well-formed and is \tcode{true}.
 Otherwise \tcode{env.query(q, a...)} is ill-formed.
 \end{itemize}