fixup! Support metric aliases in queries

metricflow/dataflow/builder/dataflow_plan_builder.py

@@ -163,6 +163,7 @@ def _build_query_output_node(
                 or metric_spec.offset_to_grain is not None
                 or metric_spec.offset_window is not None
             ):
+                # Remove aliases here. They will be added back at the very end of the query.
                 metric_specs += (metric_spec.with_alias(None),) if metric_spec.alias else (metric_spec,)
                 raise ValueError(
                     f"The metric specs in the query spec should not contain any metric modifiers. Got: {metric_spec}"