Changing EditorSpinSlider values with arrow keys does not respect tool script setters

[Razoric480]

Godot version

3.3.stable, 4.0dev 8c162f4

System information

Windows 10

Issue description

When changing the value of the editor spin slider using the arrow keys UP and DOWN on a value that gets modified by a tool script setter (I.E. clamped), the text value of the spin slider is left in its pre-script value and not properly updated.

This is because setters are called in the next idle frame, not immediately after setting the value, so we need to wait until NOTIFICATION_PROCESS before updating the text. As mentioned in #53090 (comment)

Steps to reproduce

@tool
extends Node

@export
var some_num := 1:
	get:
		return some_num
	set(value):
		some_num = clamp(value, 0, 1)

or 3.x

extends Node
tool

export var some_num := 1 setget _set_some_num

func _set_some_num(value):
	some_num = clamp(value, 0, 1)

Minimal reproduction project

No response