Use depth pass mode with normals if required even if Environment is null

If using normal buffer debugging or if the normal texture was used, we should use PASS_MODE_DEPTH_NORMAL_ROUGHNESS regardless of whether there is a valid Environment or not. Otherwise, shaders reading the normal texture will not work without a valid Environment (and possibly other problems).

servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp

@@ -1699,6 +1699,8 @@ void RenderForwardClustered::_render_scene(RenderDataRD *p_render_data, const Co
 					scene_state.used_normal_texture) {
 				depth_pass_mode = PASS_MODE_DEPTH_NORMAL_ROUGHNESS;
 			}
+		} else if (get_debug_draw_mode() == RS::VIEWPORT_DEBUG_DRAW_NORMAL_BUFFER || scene_state.used_normal_texture) {
+			depth_pass_mode = PASS_MODE_DEPTH_NORMAL_ROUGHNESS;
 		}
 
 		switch (depth_pass_mode) {