Add a SpinBox property to disable non-numeric input

[gdevgodot]

Describe the project you are working on

An in-editor game framework.

Describe the problem or limitation you are having in your project

I've noticed that when you use SpinBox node it allows you to use non-number characters and I think it only should accept number inputs.

Describe the feature / enhancement and how it helps to overcome the problem or limitation

Only allow numbers inputs.

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

When you open a SpinBox and type whatever only numbers are accepted as Input.

If this enhancement will not be used often, can it be worked around with a few lines of script?

I'm not sure if that's a great enhancement, but it could make avoid some confussions while working with SpinBox node.

Is there a reason why this should be core and not an add-on in the asset library?

This make SpinBox usability quite better.

[Calinou]

This is intended so you can enter mathematical expressions and functions (including ones that use constants like PI). For instance, enter 0.5 * PI + sqrt(2) and it'll evaluate the expression.

godotengine/godot#106327 documents this behavior in the class reference.

[gdevgodot]

I would add a boolean property or something like that for only receiving number inputs since thats the most common use.