Remove preview versions

Author: amariwest-msft

sdk/communication/azure-communication-callautomation/azure/communication/callautomation/_api_versions.py

@@ -8,9 +8,7 @@
 
 class ApiVersion(str, Enum, metaclass=CaseInsensitiveEnumMeta):
     V2023_03_06 = "2023-03-06"
-    V2023_06_15_PREVIEW = "2023-06-15-preview"
     V2023_10_15 = "2023-10-15"
-    V2023_10_03_PREVIEW = "2023-10-03-preview"
     V2024_04_15 = "2024-04-15"
 
 DEFAULT_VERSION = ApiVersion.V2024_04_15.value