chore: Remove previously deprecated dataset metrics column from RESTf…

…ul API (#24401)

UPDATING.md

@@ -34,6 +34,7 @@ assists people when migrating to a new version.
 
 ### Breaking Changes
 
+- [24401](https://github.com/apache/superset/pull/24401): Removes the deprecated `metrics` column (which was blossomed in [20732](https://github.com/apache/superset/pull/20732)) from the `/api/v1/dataset/` API.
 - [24375](https://github.com/apache/superset/pull/24375): Removed deprecated API `/superset/get_or_create_table/...`, `/superset/sqllab_viz`
 - [24360](https://github.com/apache/superset/pull/24360): Removed deprecated APIs `/superset/stop_query/...`, `/superset/queries/...`, `/superset/search_queries`
 - [24353](https://github.com/apache/superset/pull/24353): Removed deprecated APIs `/copy_dash/int:dashboard_id/`, `/save_dash/int:dashboard_id/`, `/add_slices/int:dashboard_id/`.

superset/datasets/api.py

@@ -163,7 +163,6 @@ class DatasetRestApi(BaseSupersetModelRestApi):
         "columns.type",
         "columns.uuid",
         "columns.verbose_name",
-        "metrics",  # TODO(john-bodley): Deprecate in 3.0.
         "metrics.changed_on",
         "metrics.created_on",
         "metrics.d3format",