Fix GraphEdit::frame_rect_changed signal parameter type

Changes the parameter type from Vector2 to Rect2, which is what is actually emitted.

doc/classes/GraphEdit.xml

@@ -469,7 +469,7 @@
 		</signal>
 		<signal name="frame_rect_changed">
 			<param index="0" name="frame" type="GraphFrame" />
-			<param index="1" name="new_rect" type="Vector2" />
+			<param index="1" name="new_rect" type="Rect2" />
 			<description>
 				Emitted when the [GraphFrame] [param frame] is resized to [param new_rect].
 			</description>

misc/extension_api_validation/4.3-stable.expected

@@ -319,3 +319,10 @@ GH-100913
 Validate extension JSON: Error: Field 'classes/TextEdit/methods/get_line_column_at_pos/arguments': size changed value in new API, from 2 to 3.
 
 Added optional argument to disallow positions that are outside the column range of the line. Compatibility method registered.
+
+
+GH-102796
+---------
+Validate extension JSON: Error: Field 'classes/GraphEdit/signals/frame_rect_changed/arguments/1': type changed value in new API, from "Vector2" to "Rect2".
+
+Previous type was incorrect. No compatibility system for signal arguments.

scene/gui/graph_edit.cpp

@@ -2834,7 +2834,7 @@ void GraphEdit::_bind_methods() {
 
 	ADD_SIGNAL(MethodInfo("node_selected", PropertyInfo(Variant::OBJECT, "node", PROPERTY_HINT_RESOURCE_TYPE, "Node")));
 	ADD_SIGNAL(MethodInfo("node_deselected", PropertyInfo(Variant::OBJECT, "node", PROPERTY_HINT_RESOURCE_TYPE, "Node")));
-	ADD_SIGNAL(MethodInfo("frame_rect_changed", PropertyInfo(Variant::OBJECT, "frame", PROPERTY_HINT_RESOURCE_TYPE, "GraphFrame"), PropertyInfo(Variant::VECTOR2, "new_rect")));
+	ADD_SIGNAL(MethodInfo("frame_rect_changed", PropertyInfo(Variant::OBJECT, "frame", PROPERTY_HINT_RESOURCE_TYPE, "GraphFrame"), PropertyInfo(Variant::RECT2, "new_rect")));
 
 	ADD_SIGNAL(MethodInfo("popup_request", PropertyInfo(Variant::VECTOR2, "at_position")));