Mention unsafe loading

[ghost]

Your Godot version:

4.0 stable

Issue description:
I watched this video https://www.youtube.com/watch?v=j7p7cGj20jU and it said they talked to the devs but I don't see the docs mention malicious code anywhere. I think it should be mentioned on the following pages if people want to use it to save and load.

URL to the documentation page (if already existing):

https://docs.godotengine.org/en/stable/tutorials/io/saving_games.html
https://docs.godotengine.org/en/stable/classes/class_configfile.html#class-configfile-method-save
https://docs.godotengine.org/en/stable/classes/class_resourcesaver.html#class-resourcesaver-method-save
https://docs.godotengine.org/en/stable/classes/class_fileaccess.html#class-fileaccess-method-store-var

[ghost]

I have been informed that this is not the game developer's problem on Discord.

[Calinou]

• See Provide a way to load resources without running scripts godot-proposals#4925.

I have been informed that this is not the game developer's problem on Discord.

I would prefer avoiding steering people towards using JSON saves again, as it's a lot less convenient.