Make assert behavior consistent with documentation.

[jitspoe]

Execution can resume from the debugger and will continue executing code in the function instead of bailing out early.

Fix for #34054

[dalexeev]

If you find a difference between the engine's behavior and the documentation, it does not necessarily mean that there is a bug in the engine. Documentation can have errors too.

In my opinion, the current behavior is more reasonable. As far as I know, in most languages, failure to satisfy assert conditions either results in abnormal program termination or throws an exception. Godot/GDScript doesn't have exceptions, so their shallow equivalent in this case is function exit. This is quite reasonable: if the assert condition is not met, then a significant logical error has occurred somewhere, the function's expectations are fundamentally broken, and continuing its execution makes no sense and may even be dangerous.

You might argue that this creates a difference between debug and release versions. But this difference also exists in other languages ​​where you can disable assertions. The mechanism by which assert works is not important here: whether it terminates the program abnormally, throws an exception, or exits the function - there will be differences between the versions with assertions enabled and disabled, that's the idea behind assert. The only thing that matters is its behavior in the debug version, not the differences between the debug and release versions.

• See also Asserts should not make the function return godot-proposals#13111.

[jitspoe]

Probably makes more sense to keep discussions on the proposal, so I've made a comment there: godotengine/godot-proposals#13111 (comment)