update readmes (#26125)

Author: FumingZhang

specification/containerservice/resource-manager/Microsoft.ContainerService/aks/readme.java.md

@@ -82,6 +82,20 @@ batch:
   - tag: package-2023-07
   - tag: package-preview-2023-08
   - tag: package-2023-08
+  - tag: package-2023-09
+```
+
+### Tag: package-2023-09 and java
+
+These settings apply only when `--tag=package-2023-09` is specified on the command line.
+Please also specify `--azure-libraries-for-java-folder=<path to the root directory of your azure-sdk-for-java clone>`.
+
+``` yaml $(tag) == 'package-2023-09' && $(java) && $(multiapi)
+java:
+  namespace: com.microsoft.azure.management.containerservice.v2023_09_01
+  output-folder: $(azure-libraries-for-java-folder)/sdk/containerservice/mgmt-v2023_09_01
+regenerate-manager: true
+generate-interface: true
 ```
 
 ### Tag: package-2023-08 and java

specification/containerservice/resource-manager/Microsoft.ContainerService/aks/readme.python.md

@@ -16,9 +16,10 @@ no-namespace-folders: true
 Generate all API versions currently shipped for this package
 
 ```yaml $(python)
-default-api-version: "2023-08-01"
+default-api-version: "2023-09-01"
 multiapi: true
 batch:
+  - tag: package-2023-09
   - tag: package-2023-08
   - tag: package-preview-2023-08
   - tag: package-2023-07
@@ -94,6 +95,16 @@ perform-load: false
 clear-output-folder: false
 ```
 
+### Tag: package-2023-09 and python
+
+These settings apply only when `--tag=package-2023-09 --python` is specified on the command line.
+Please also specify `--python-sdks-folder=<path to the root directory of your azure-sdk-for-python clone>`.
+
+``` yaml $(tag) == 'package-2023-09' && $(python)
+namespace: azure.mgmt.containerservice.v2023_09_01
+output-folder: $(python-sdks-folder)/containerservice/azure-mgmt-containerservice/azure/mgmt/containerservice/v2023_09_01
+```
+
 ### Tag: package-2023-08 and python
 
 These settings apply only when `--tag=package-2023-08 --python` is specified on the command line.