fix: sorting by saved metric (#13059)

superset/connectors/sqla/models.py

@@ -1150,6 +1150,8 @@ class SqlaTable(  # pylint: disable=too-many-public-methods,too-many-instance-at
                 col = self.adhoc_metric_to_sqla(col, columns_by_name)
             elif col in columns_by_name:
                 col = columns_by_name[col].get_sqla_col()
+            elif col in metrics_by_name:
+                col = metrics_by_name[col].get_sqla_col()
 
             if isinstance(col, Label):
                 label = col._label  # pylint: disable=protected-access

superset/examples/birth_names.py

@@ -271,8 +271,8 @@ def create_slices(
                 groupby=["name"],
                 adhoc_filters=[gen_filter("gender", "girl")],
                 row_limit=50,
-                timeseries_limit_metric="sum__num",
-                metrics=metrics,
+                timeseries_limit_metric=metric,
+                metrics=[metric],
             ),
         ),
         Slice(
@@ -300,7 +300,8 @@ def create_slices(
                 groupby=["name"],
                 adhoc_filters=[gen_filter("gender", "boy")],
                 row_limit=50,
-                metrics=metrics,
+                timeseries_limit_metric=metric,
+                metrics=[metric],
             ),
         ),
         Slice(