Core#Dereferencing example schema: remove second dimension of array

Author: notEthan

jsonschema-core.xml

@@ -1741,10 +1741,8 @@
 <![CDATA[
 {
     "$id": "https://example.net/root.json",
-    "items": {
-        "type": "array",
-        "items": { "$ref": "#item" }
-    },
+    "type": "array",
+    "items": { "$ref": "#item" },
     "$defs": {
         "single": {
             "$anchor": "item",