AzureTerrform: Remove the parallelism property (Azure#18909)

Author: magodo

specification/terraform/resource-manager/Microsoft.AzureTerraform/preview/2023-07-01-preview/export.json

@@ -289,12 +289,6 @@
           "description": "Whether to output all non-computed properties in the generated Terraform configuration? This probably needs manual modifications to make it valid",
           "type": "boolean",
           "default": false
-        },
-        "parallelism": {
-          "description": " Limit the number of parallel operations, i.e., resource discovery, import",
-          "type": "integer",
-          "format": "int64",
-          "default": 10
         }
       },
       "type": "object"