refactor: Migrates legacy Sunburst charts to ECharts and removes legacy code (#26350)

superset/examples/configs/charts/Vaccine_Candidates_per_Country__Stage.yaml

@@ -15,14 +15,14 @@
 # specific language governing permissions and limitations
 # under the License.
 slice_name: Vaccine Candidates per Country & Stage
-viz_type: sunburst
+viz_type: sunburst_v2
 params:
   adhoc_filters: []
   color_scheme: supersetColors
   datasource: 69__table
-  groupby:
-  - product_category
-  - clinical_stage
+  columns:
+    - product_category
+    - clinical_stage
   linear_color_scheme: schemeYlOrBr
   metric: count
   queryFields:
@@ -33,7 +33,7 @@ params:
   slice_id: 3964
   time_range: No filter
   url_params: {}
-  viz_type: sunburst
+  viz_type: sunburst_v2
 cache_timeout: null
 uuid: f69c556f-15fe-4a82-a8bb-69d5b6954123
 version: 1.0.0