[ReleasePR datafactory] Update swagger for SSIS IR to support SSISDB failover (#1336)

Create to sync Azure/azure-rest-api-specs#12357
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Author: msftbot[bot]

schemas/2017-09-01-preview/Microsoft.DataFactory.json

@@ -12175,4 +12175,4 @@
       "description": "Zoho server dataset."
     }
   }
-}
+}

schemas/2018-06-01/Microsoft.DataFactory.json

@@ -15790,6 +15790,10 @@
         "catalogServerEndpoint": {
           "type": "string",
           "description": "The catalog database server URL."
+        },
+        "dualStandbyPairName": {
+          "type": "string",
+          "description": "The dual standby pair name of Azure-SSIS Integration Runtimes to support SSISDB failover."
         }
       },
       "description": "Catalog information for managed dedicated integration runtime."
@@ -28189,4 +28193,4 @@
       "description": "A copy activity Zoho server source."
     }
   }
-}
+}