### Godot version

4.2.dev 5ee983188de97ae027f9b9c1443438063f708a7e

### System information

Windows 10 - Compatibility renderer 

### Issue description

When running a VR project sky contribution is not working in the compatibility renderer:

![image](https://github.com/godotengine/godot/assets/1945449/7aa19569-95c8-41a2-913b-37b81f4728a7)

It is working fine in normal mode. Can be worked around by setting sky contribution to 0 and providing an ambient color.

### Steps to reproduce

Try any project with a proper sky setup in XR, just switch to compatibility renderer.

### Minimal reproduction project

I'll try and create an MVP soon that can be used without XR hardware, but for now this can be used:
https://github.com/BastiaanOlij/godot_openxr_demo
float NdotH2 = NdotH * NdotH;
	float denom = (NdotH2 * (roughness4 - 1.0) + 1.0);
	denom = Math_PI * denom * denom;
	return roughness4 / denom;
}
float radical_inverse_vdC(uint32_t bits) {
	bits = (bits << 16) | (bits >> 16);
	bits = ((bits & 0x55555555) << 1) | ((bits & 0xAAAAAAAA) >> 1);
	bits = ((bits & 0x33333333) << 2) | ((bits & 0xCCCCCCCC) >> 2);
	bits = ((bits & 0x0F0F0F0F) << 4) | ((bits & 0xF0F0F0F0) >> 4);
	bits = ((bits & 0x00FF00FF) << 8) | ((bits & 0xFF00FF00) >> 8);
	return float(bits) * 2.3283064365386963e-10;
}
Vector2 hammersley(uint32_t i, uint32_t N) {
	return Vector2(float(i) / float(N), radical_inverse_vdC(i));
}
void RasterizerSceneGLES3::_filter_sky_radiance(Sky *p_sky, int p_base_layer) {
	GLES3::MaterialStorage *material_storage = GLES3::MaterialStorage::get_singleton();
	glActiveTexture(GL_TEXTURE0);
	glBindTexture(GL_TEXTURE_CUBE_MAP, p_sky->raw_radiance);
	glBindFramebuffer(GL_FRAMEBUFFER, p_sky->radiance_framebuffer);
	CubemapFilterShaderGLES3::ShaderVariant mode = CubemapFilterShaderGLES3::MODE_DEFAULT;
	if (p_base_layer == 0) {
		glGenerateMipmap(GL_TEXTURE_CUBE_MAP);
		
		mode = CubemapFilterShaderGLES3::MODE_COPY;
	}
	int size = p_sky->radiance_size >> p_base_layer;
	glViewport(0, 0, size, size);