### Godot version

v4.0.beta12.official [3c9bf4bc2]

### System information

Windows 10, AMD Radeon RX 480 4 GB RAM, 16 gb ram, Intel CPU 4 cores.

### Issue description


When switching to mobile render from forward + The alpha texture on the tree mesh starts to flicker.
Made a video: https://www.youtube.com/watch?v=WdGVi1hdRHo



### Steps to reproduce

Switching to mobile render from forward +

### Minimal reproduction project

Uploaded the project in google link: https://drive.google.com/file/d/1efEV914CWkyWoGzkv3RBMnw9t-4BVTeQ/view?usp=sharing
(only deleted the .godot - i guess its not needed.)
Transform2D xf = p_viewport->global_transform;
	float scale = 1.0;
	if (p_viewport->canvas_map.has(p_canvas->parent)) {
		Transform2D c_xform = p_viewport->canvas_map[p_canvas->parent].transform;
		if (p_viewport->snap_2d_transforms_to_pixel) {
			c_xform.columns[2] = c_xform.columns[2].floor();
		}
		xf = xf * c_xform;
		scale = p_canvas->parent_scale;
	}
	Transform2D c_xform = p_canvas_data->transform;
	if (p_viewport->snap_2d_transforms_to_pixel) {
		c_xform.columns[2] = c_xform.columns[2].floor();
	}
	xf = xf * c_xform;
	if (scale != 1.0 && !RSG::canvas->disable_scale) {
		Vector2 pivot = p_vp_size * 0.5;
		Transform2D xfpivot;
		xfpivot.set_origin(pivot);
		Transform2D xfscale;
		xfscale.scale(Vector2(scale, scale));
		xf = xfpivot.affine_inverse() * xf;
		xf = xfscale * xf;
		xf = xfpivot * xf;
	}
	return xf;
}
Vector<RendererViewport::Viewport *> RendererViewport::_sort_active_viewports() {