[synapse] Mark 'sparkJobs' as nullable (#12258)

chamons · web-flow · commit 0059a6a70377 · 2021-01-11T08:18:33.000+13:00
```System.Text.Json.JsonException : A property 'sparkJobs' defined as non-nullable but received as null from the service. This exception only happens in DEBUG builds of the library and would be ignored in the release build```
diff --git a/specification/synapse/data-plane/Microsoft.Synapse/preview/2019-11-01-preview/monitoring.json b/specification/synapse/data-plane/Microsoft.Synapse/preview/2019-11-01-preview/monitoring.json
@@ -129,7 +129,8 @@
           "type": "array",
           "items": {
             "$ref": "#/definitions/SparkJob"
-          }
+          },
+          "x-nullable": true
         }
       }
     },

Original file line number	Diff line number	Diff line change
`@@ -129,7 +129,8 @@`
`129`	`129`	`"type": "array",`
`130`	`130`	`"items": {`
`131`	`131`	`"$ref": "#/definitions/SparkJob"`
`132`		`- }`
	`132`	`+ },`
	`133`	`+ "x-nullable": true`
`133`	`134`	`}`
`134`	`135`	`}`
`135`	`136`	`},`