Use a smaller epsilon for omni and spot attenuation cutoff

We just want to avoid calculating shadows when the attenuation is zero, so we should use the smallest epsilon we can get away with

servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl

@@ -120,7 +120,7 @@ void light_compute(vec3 N, vec3 L, vec3 V, float A, vec3 light_color, bool is_di
 #endif
 
 	// We skip checking on attenuation on directional lights to avoid a branch that is not as beneficial for directional lights as the other ones.
-	const float EPSILON = 1e-3f;
+	const float EPSILON = 1e-6f;
 	if (is_directional || attenuation > EPSILON) {
 		float cNdotL = max(NdotL, 0.0);
 #if defined(DIFFUSE_BURLEY) || defined(SPECULAR_SCHLICK_GGX) || defined(LIGHT_CLEARCOAT_USED)
@@ -405,7 +405,7 @@ void light_process_omni(uint idx, vec3 vertex, vec3 eye_vec, vec3 normal, vec3 v
 		vec3 binormal, vec3 tangent, float anisotropy,
 #endif
 		inout vec3 diffuse_light, inout vec3 specular_light) {
-	const float EPSILON = 1e-3f;
+	const float EPSILON = 1e-6f;
 
 	// Omni light attenuation.
 	vec3 light_rel_vec = omni_lights.data[idx].position - vertex;
@@ -700,7 +700,7 @@ void light_process_spot(uint idx, vec3 vertex, vec3 eye_vec, vec3 normal, vec3 v
 #endif
 		inout vec3 diffuse_light,
 		inout vec3 specular_light) {
-	const float EPSILON = 1e-3f;
+	const float EPSILON = 1e-6f;
 
 	// Spot light attenuation.
 	vec3 light_rel_vec = spot_lights.data[idx].position - vertex;