### Godot version

4.0.beta10.official [d0398f62f]

### System information

Windows 10, Vulkan, NVIDIA GeForce RTX 2060m (31.0.15.2698)

### Issue description

I'm getting some kind of clustering/blocky artifact when using spotlights, with no fog or any fancy rendering stuff whatsoever.
I've looked through a bunch of similar issues, but the only ones I could find were related to volumetric fog or other environment effects that I am not using.
Not sure if I'm just missing something, but I think I've played with every option in the spotlight and every option in a WorldEnvironment and nothing makes it go away.

The only lead I have is that the intensity of the artifact seems to be affected by the spot angle. It cycles in a sawtooth pattern every ~0.07 degrees.

![image](https://user-images.githubusercontent.com/13819558/209914720-77a637ea-8cc7-4cff-8216-363f9150885a.png)

Lmk if you need more info or need me to try anything.

### Steps to reproduce

1. New Project (Forward+)
2. Put down some MeshInstance3Ds as a backdrop
3. Put a SpotLight3D
4. Raise spotlight intensity, lower spot angle, and increase range to see it better
5. Slowly increase spot angle to see cycling effect

### Minimal reproduction project

[testspotlight.zip](https://github.com/godotengine/godot/files/10318069/testspotlight.zip)

Light3D(RenderingServer::LIGHT_OMNI) {
	set_shadow_mode(SHADOW_CUBE);
}
PackedStringArray SpotLight3D::get_configuration_warnings() const {
	PackedStringArray warnings = Light3D::get_configuration_warnings();
	if (has_shadow() && get_param(PARAM_SPOT_ANGLE) >= 90.0) {
		warnings.push_back(RTR("A SpotLight3D with an angle wider than 90 degrees cannot cast shadows."));
	}
	if (!has_shadow() && get_projector().is_valid()) {
		warnings.push_back(RTR("Projector texture only works with shadows active."));
	}
	return warnings;
}
void SpotLight3D::_bind_methods() {
	ADD_GROUP("Spot", "spot_");
	ADD_PROPERTYI(PropertyInfo(Variant::FLOAT, "spot_range", PROPERTY_HINT_RANGE, "0,4096,0.001,or_greater,exp,suffix:m"), "set_param", "get_param", PARAM_RANGE);
	ADD_PROPERTYI(PropertyInfo(Variant::FLOAT, "spot_attenuation", PROPERTY_HINT_EXP_EASING, "attenuation"), "set_param", "get_param", PARAM_ATTENUATION);
	ADD_PROPERTYI(PropertyInfo(Variant::FLOAT, "spot_angle", PROPERTY_HINT_RANGE, "0,180,0.01,degrees"), "set_param", "get_param", PARAM_SPOT_ANGLE);
	ADD_PROPERTYI(PropertyInfo(Variant::FLOAT, "spot_angle_attenuation", PROPERTY_HINT_EXP_EASING, "attenuation"), "set_param", "get_param", PARAM_SPOT_ATTENUATION);
}
SpotLight3D::SpotLight3D() :
		Light3D(RenderingServer::LIGHT_SPOT) {
	
	set_param(PARAM_SHADOW_BIAS, 0.03);
}