Removed unwanted type: object on endpoint and fixed broken sample.

Signed-off-by: Jean-Baptiste Bianchi <jb.bianchi@neuroglia.io>

Author: JBBianchi

dsl-reference.md

@@ -178,7 +178,7 @@ use:
       call: openapi
       with:
         document:
-          uri: https://petstore.swagger.io/v2/swagger.json
+          endpoint: https://petstore.swagger.io/v2/swagger.json
         operationId: findByStatus
         parameters:
           status: available

schema/workflow.yaml

@@ -1003,7 +1003,6 @@ $defs:
         description: A human-readable explanation specific to this occurrence of the error.
     required: [ type, status, instance ]
   endpoint:
-    type: object
     title: Endpoint
     description: Represents an endpoint.
     oneOf: