remove redundancy in properties annotation definition

Author: gregsdennis

jsonschema-core.xml

@@ -2404,7 +2404,7 @@
                         </t>
                         <t>
                             The annotation result of this keyword is the set of instance
-                            property names which are present in both this keyword and the instance.
+                            property names which are also present in this keyword.
                             This annotation affects the behavior of "additionalProperties" (in
                             this vocabulary) and "unevaluatedProperties" in the Unevaluated vocabulary.
                         </t>