### 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.)
ERR_FAIL_COND_MSG(p_repeat == RS::CANVAS_ITEM_TEXTURE_REPEAT_DEFAULT, "Viewport does not accept DEFAULT as texture repeat (it's the topmost choice already).)");
	Viewport *viewport = viewport_owner.get_or_null(p_viewport);
	ERR_FAIL_COND(!viewport);
	viewport->texture_repeat = p_repeat;
}
void RendererViewport::viewport_set_sdf_oversize_and_scale(RID p_viewport, RS::ViewportSDFOversize p_size, RS::ViewportSDFScale p_scale) {
	Viewport *viewport = viewport_owner.get_or_null(p_viewport);
	ERR_FAIL_COND(!viewport);
	RSG::texture_storage->render_target_set_sdf_size_and_scale(viewport->render_target, p_size, p_scale);
}
RID RendererViewport::viewport_find_from_screen_attachment(DisplayServer::WindowID p_id) const {
	RID *rids = nullptr;
	uint32_t rid_count = viewport_owner.get_rid_count();
	rids = (RID *)alloca(sizeof(RID *) * rid_count);
	viewport_owner.fill_owned_buffer(rids);
	for (uint32_t i = 0; i < rid_count; i++) {
		Viewport *viewport = viewport_owner.get_or_null(rids[i]);
		if (viewport->viewport_to_screen == p_id) {
			return rids[i];
		}
	}
	return RID();
}
void RendererViewport::viewport_set_vrs_mode(RID p_viewport, RS::ViewportVRSMode p_mode) {
	Viewport *viewport = viewport_owner.get_or_null(p_viewport);
	ERR_FAIL_COND(!viewport);
	RSG::texture_storage->render_target_set_vrs_mode(viewport->render_target, p_mode);
	_configure_3d_render_buffers(viewport);
}
void RendererViewport::viewport_set_vrs_texture(RID p_viewport, RID p_texture) {