(AzureCXP) fixes MicrosoftDocs/azure-docs#122301

.NET 8.0.0 is the latest release for the entire .NET framework and APIM SDK version is v1.1.0 https://github.com/Azure/azure-sdk-for-net/blob/main/sdk/apimanagement/Azure.ResourceManager.ApiManagement/CHANGELOG.md
so modified the doc accordingly.

Author: Jar1-MSFT

articles/api-management/breaking-changes/api-version-retirement-sep-2023.md

@@ -47,7 +47,7 @@ We also recommend setting the **Minimum API version** in your API Management ins
     * Terraform azurerm provider: 3.0.0
 
 * **Azure SDKs** - Update the Azure API Management SDKs to the latest versions or at least the following versions: 
-    * .NET: 8.0.0 
+    * .NET: v1.1.0 
     * Go: 1.0.0 
     * Python: 3.0.0 
    - JavaScript: 8.0.1 
@@ -79,4 +79,4 @@ To set the **Minimum API version** in the portal:
 
 ## Related content
 
-See all [upcoming breaking changes and feature retirements](overview.md).
+See all [upcoming breaking changes and feature retirements](overview.md).