### Godot version

4.0.2.stable (7a0977c)

### System information

Ubuntu 22.04, x86_64, LLVM

### Issue description

When performing a dedicated server export with:
- a `ShaderMaterial` (a `canvas_item` shader used on a `Panel` in the example below)
- a build with `disable_3d=yes`

the resulting export gives the following error when run:
```
ERROR: Cannot get class 'PlaceholderMaterial'.
   at: instantiate (core/object/class_db.cpp:326)
ERROR: res://main.tscn:Resource of unrecognized type in file: PlaceholderMaterial.
   at: load (core/io/resource_format_binary.cpp:778)
ERROR: Failed loading resource: res://.godot/exported/206107301/export-3070c538c03ee49b7677ff960a3f5195-main.scn. Make sure resources have been imported by opening the project in the editor at least once.
   at: _load (core/io/resource_loader.cpp:223)
ERROR: Failed loading scene: res://main.tscn
   at: start (main/main.cpp:2965)
```

I would expect things to work here without an error - there's no 3D in use here and a normal export with the same build does run as expected.

### Steps to reproduce

1. Build godot with `disable_3d=yes`.
2. Create a new project, and add a `Panel` node.
3. Add a `canvas_item` shader as the material for the `Panel` node.
4. Perform a dedicated server export using the build from step 1.
5. Run the exported binary and observe the error.

### Minimal reproduction project

[DedicatedServer2DTest.zip](https://github.com/godotengine/godot/files/11597444/DedicatedServer2DTest.zip)

OS::get_singleton()->yield(); 
	bool swap_cancel_ok = false;
	if (DisplayServer::get_singleton()) {
		swap_cancel_ok = GLOBAL_DEF_NOVAL("gui/common/swap_cancel_ok", bool(DisplayServer::get_singleton()->get_swap_cancel_ok()));
	}
	AcceptDialog::set_swap_cancel_ok(swap_cancel_ok);
#endif
	
	GDREGISTER_CLASS(AnimationPlayer);
	GDREGISTER_CLASS(Tween);
	GDREGISTER_ABSTRACT_CLASS(Tweener);
	GDREGISTER_CLASS(PropertyTweener);
	GDREGISTER_CLASS(IntervalTweener);
	GDREGISTER_CLASS(CallbackTweener);
	GDREGISTER_CLASS(MethodTweener);
	GDREGISTER_CLASS(AnimationTree);
	GDREGISTER_CLASS(AnimationNode);
	GDREGISTER_CLASS(AnimationRootNode);
	GDREGISTER_CLASS(AnimationNodeBlendTree);
	GDREGISTER_CLASS(AnimationNodeBlendSpace1D);
	GDREGISTER_CLASS(AnimationNodeBlendSpace2D);
	GDREGISTER_CLASS(AnimationNodeStateMachine);
	GDREGISTER_CLASS(AnimationNodeStateMachinePlayback);
	GDREGISTER_CLASS(AnimationNodeSync);
	GDREGISTER_CLASS(AnimationNodeStateMachineTransition);
	GDREGISTER_CLASS(AnimationNodeOutput);
	GDREGISTER_CLASS(AnimationNodeOneShot);
	GDREGISTER_CLASS(AnimationNodeAnimation);
	GDREGISTER_CLASS(AnimationNodeAdd2);
	GDREGISTER_CLASS(AnimationNodeAdd3);