fix: expect fields in meta

Author: zachdaniel

lib/ash_json_api/request.ex

@@ -977,10 +977,14 @@ defmodule AshJsonApi.Request do
     end
   end
 
-  defp relationship_change_value(_name, value) when is_nil(value) or is_map(value) do
+  defp relationship_change_value(_name, value) when is_nil(value) do
     {:ok, value}
   end
 
+  defp relationship_change_value(_name, %{"meta" => meta}) when is_map(meta) do
+    {:ok, meta}
+  end
+
   defp relationship_change_value(name, value) do
     {:error, InvalidRelationshipInput.exception(relationship: name, input: value)}
   end