Update functions-reference-java.md

Removing the note about cold start since ~2 and ~3 will go out of support in December:
> The value of AppSetting FUNCTIONS_EXTENSION_VERSION should be ~2 or ~3 for an optimized cold start experience.

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cc: @ggailey777

Author: MadhuraBharadwaj-MSFT

articles/azure-functions/functions-reference-java.md

@@ -554,9 +554,6 @@ public class Function {
 
 ```
 
-> [!NOTE]
-> The value of AppSetting FUNCTIONS_EXTENSION_VERSION should be ~2 or ~3 for an optimized cold start experience.
-
 ## Next steps
 
 For more information about Azure Functions Java development, see the following resources: