[test][protocoltemplateeditor] Cleaned declaration file retrieval

beat/editor/test/test_protocoletemplateditor.py

@@ -104,12 +104,11 @@ class TestProtocolTemplateEditor:
     """Test that the protocol template editor works correctly"""
 
     def test_load_and_dump(self, qtbot, test_prefix):
-        asset_model = AssetModel()
-        asset_model.asset_type = AssetType.PROTOCOLTEMPLATE
-        asset_model.prefix_path = test_prefix
         asset_name = "double/1"
 
-        with open(asset_model.json_path(asset_name), "rt") as json_file:
+        with open(
+            AssetType.PROTOCOLTEMPLATE.declaration_path(test_prefix, asset_name), "rt"
+        ) as json_file:
             json_data = json.load(json_file)
             editor = ProtocolTemplateEditor()
             editor.load_json(json_data)