### 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)

shadow_mode = p_mode;
	RS::get_singleton()->light_omni_set_shadow_mode(light, RS::LightOmniShadowMode(p_mode));
}
OmniLight3D::ShadowMode OmniLight3D::get_shadow_mode() const {
	return shadow_mode;
}
PackedStringArray OmniLight3D::get_configuration_warnings() const {
	PackedStringArray warnings = Light3D::get_configuration_warnings();
	if (!has_shadow() && get_projector().is_valid()) {
		warnings.push_back(RTR("Projector texture only works with shadows active."));
	}
	return warnings;
}
void OmniLight3D::_bind_methods() {
	ClassDB::bind_method(D_METHOD("set_shadow_mode", "mode"), &OmniLight3D::set_shadow_mode);
	ClassDB::bind_method(D_METHOD("get_shadow_mode"), &OmniLight3D::get_shadow_mode);
	ADD_GROUP("Omni", "omni_");
	ADD_PROPERTYI(PropertyInfo(Variant::FLOAT, "omni_range", PROPERTY_HINT_RANGE, "0,4096,0.001,or_greater,exp"), "set_param", "get_param", PARAM_RANGE);
	ADD_PROPERTYI(PropertyInfo(Variant::FLOAT, "omni_attenuation", PROPERTY_HINT_EXP_EASING, "attenuation"), "set_param", "get_param", PARAM_ATTENUATION);
	ADD_PROPERTY(PropertyInfo(Variant::INT, "omni_shadow_mode", PROPERTY_HINT_ENUM, "Dual Paraboloid,Cube"), "set_shadow_mode", "get_shadow_mode");
	BIND_ENUM_CONSTANT(SHADOW_DUAL_PARABOLOID);
	BIND_ENUM_CONSTANT(SHADOW_CUBE);
}
OmniLight3D::OmniLight3D() :