Add subtest for synthetics multistep tests (#3269)

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: