PEP 13: clarify a sentence

Someone pointed out "with not veto by the steering council" could be misconstrued as suggesting the SC has no veto powers when it actually does.

pep-0013.rst

@@ -266,7 +266,7 @@ Core team membership acknowledges sustained and valuable efforts that
 align well with the philosophy and the goals of the Python project.
 
 It is granted by receiving at least two-thirds positive votes in a
-core team vote that is open for one week and with no veto by the
+core team vote that is open for one week and is not vetoed by the
 steering council.
 
 Core team members are always looking for promising contributors,