update mysql readme.typescript (Azure#23989)

Author: kazrael2119

specification/mysql/resource-manager/readme.typescript.md

@@ -9,12 +9,12 @@ typescript:
   generate-metadata: true
 ```
 
-### Tag: package-flexibleserver-2021-05-01 and TypeScript
+### Tag: package-flexibleserver-2022-09-30-preview and TypeScript
 
-These settings apply only when `--tag=package-flexibleserver-2021-05-01 --typescript` is specified on the command line.
+These settings apply only when `--tag=package-flexibleserver-2022-09-30-preview --typescript` is specified on the command line.
 Please also specify `--typescript-sdks-folder=<path to the root directory of your azure-sdk-for-typescript clone>`.
 
-``` yaml $(tag) == 'package-flexibleserver-2021-05-01' && $(typescript)
+``` yaml $(tag) == 'package-flexibleserver-2022-09-30-preview' && $(typescript)
 title: MySQLManagementFlexibleServerClient
 package-name: "@azure/arm-mysql-flexible"
 output-folder: "$(typescript-sdks-folder)/sdk/mysql/arm-mysql-flexible/"