Godot version

4.0 RC2

System information

Ubuntu 22.04

Issue description

There are too noticeable "wave" artifacts when using Mobile backend to render dark scenes with a spotlight. Foward+ shows also these but in a much lesser extent. I know that the mobile renderer has an inferior quality. However these artifacts are too visible. As an example, the second image is rendered by opengl 3 using Godot 3.5.1. Maybe is about documentation on how to improve these situations to look smoother.

Steps to reproduce

Add a spot light to a dark scene using mobile renderer.

Minimal reproduction project

mobile-light-report.zip