feat(functions): runtime migration (#4735)

* feat(functions): runtime migration

* Update pages/serverless-functions/faq.mdx

Co-authored-by: Rowena Jones <[email protected]>

* Update pages/serverless-functions/faq.mdx

---------

Co-authored-by: SamyOubouaziz <[email protected]>
Co-authored-by: Rowena Jones <[email protected]>

Author: 3 people

pages/serverless-functions/faq.mdx

@@ -10,7 +10,7 @@ category: serverless
 productIcon: FunctionsProductIcon
 ---
 
-## Overview 
+## Overview
 
 ### What is serverless computing, and how does it differ from traditional cloud hosting?
 
@@ -209,8 +209,9 @@ Check out our [serverless-examples repository](https://github.com/scaleway/serve
 
 ### How to migrate runtimes?
 
-There are no constraints when changing a function runtime, you simply need to choose the runtime version you want.
-Upgrading a runtime is highly recommended in case of deprecation, and for runtimes that have reached end-of-support or end-of-life. See the [functions runtimes lifecycle documentation](/serverless-functions/reference-content/functions-runtimes/) for more information.
+On a Serverless Function, you can change the runtime if the new runtime is from the same family as the old one. Example: migrate from `go1.23` to `go1.24`. To change programming language, you must create a new Serverless Function.
+
+See the [functions runtimes lifecycle documentation](/serverless-functions/reference-content/functions-runtimes/) for more information about runtimes.
 
 ## Network and storage