[handler.functions] Replace 'shall synchronize with' with 'synchronizes with'

Author: eisenwave

source/lib-intro.tex

@@ -3341,7 +3341,7 @@
 
 \pnum
 Calling the \tcode{set_*} and \tcode{get_*} functions shall not incur a data race\iref{intro.races}.
-A call to any of the \tcode{set_*} functions shall synchronize with subsequent calls to the same
+A call to any of the \tcode{set_*} functions synchronizes with subsequent calls to the same
 \tcode{set_*} function and to the corresponding \tcode{get_*} function.
 
 \rSec3[res.on.functions]{Other functions}