Add subtest for synthetics multistep tests (#3078)

Co-authored-by: ci.datadog-api-spec <packages@datadoghq.com>

Author: api-clients-generation-pipeline[bot]

.generator/schemas/v1/openapi.yaml

@@ -3865,7 +3865,6 @@ components:
 
             points (group distributions use the roll-up modifier).'
           format: int64
-          minimum: 1
           type: integer
       type: object
     Host:

src/datadog_api_client/v1/model/heat_map_widget_x_axis.py

@@ -14,12 +14,6 @@
 
 
 class HeatMapWidgetXAxis(ModelNormal):
-    validations = {
-        "num_buckets": {
-            "inclusive_minimum": 1,
-        },
-    }
-
     @cached_property
     def openapi_types(_):
         return {