Remove non-required phrasing

Author: Relequestual

jsonschema-core.xml

@@ -1880,9 +1880,7 @@
                 </section>
                 <section title="Differing and Default Dialects">
                     <t>
-                        In addition to the rules defining the use of
-                        <xref target="keyword-schema">the "$schema" keyword</xref>,
-                        if multiple schema resources are present in a single document, then
+                        If multiple schema resources are present in a single document, then
                         schema resources which do not have a "$schema" keyword in their root
                         schema object MUST be processed as if "$schema" were present with the
                         same value as for the immediately enclosing resource.