Fix: Prevent formatting=false throwing an error (#4819)

Author: erindru

sqlmesh/core/model/definition.py

@@ -2886,6 +2886,7 @@ def render_expression(
             for name, args in values
         )
     ),
+    "formatting": str,
 }
 
 

tests/core/test_model.py

@@ -9973,9 +9973,9 @@ def test_formatting_flag_serde():
     )
 
     model = load_sql_based_model(expressions)
+    assert model.render_definition()[0].sql() == "MODEL (\nname test_model,\nformatting False\n)"
 
     model_json = model.json()
-
     assert "formatting" not in json.loads(model_json)
 
     deserialized_model = SqlModel.parse_raw(model_json)