### Godot version

v4.0.beta.custom_build [0a9e6e478]

### System information

Ubuntu, Nvidia, Vulkan

### Issue description

When a Camera2D is freed - either explicitly or by being a child of a scene that is being switched away from via a method like `get_tree().change_scene_to_file()` - then this camera somehow stays active instead of Godot properly switching to no-camera-mode.

`get_viewport().get_camera_2d()` then returns all sorts of funny things from `<Freed Object>`  (it's supposed to return `null`) to arbitrary nodes of the current scene (not cameras).

This can lead to crashes.

### Steps to reproduce

checkout the MRP.

note that the "Go to scene 2" button switches places after pressing it.
that is because a camera is still active that does not exist in the current tree.

restart it a couple of times and spam the "Go to scene 2" button.
notice the garbage output.

### Minimal reproduction project

[godot_4_camera_bug.zip](https://github.com/godotengine/godot/files/10560455/godot_4_camera_bug.zip)
BIND_ENUM_CONSTANT(DEBUG_DRAW_CLUSTER_OMNI_LIGHTS);
	BIND_ENUM_CONSTANT(DEBUG_DRAW_CLUSTER_SPOT_LIGHTS);
	BIND_ENUM_CONSTANT(DEBUG_DRAW_CLUSTER_DECALS);
	BIND_ENUM_CONSTANT(DEBUG_DRAW_CLUSTER_REFLECTION_PROBES);
	BIND_ENUM_CONSTANT(DEBUG_DRAW_OCCLUDERS)
	BIND_ENUM_CONSTANT(DEBUG_DRAW_MOTION_VECTORS)
	BIND_ENUM_CONSTANT(DEFAULT_CANVAS_ITEM_TEXTURE_FILTER_NEAREST);
	BIND_ENUM_CONSTANT(DEFAULT_CANVAS_ITEM_TEXTURE_FILTER_LINEAR);
	BIND_ENUM_CONSTANT(DEFAULT_CANVAS_ITEM_TEXTURE_FILTER_LINEAR_WITH_MIPMAPS);
	BIND_ENUM_CONSTANT(DEFAULT_CANVAS_ITEM_TEXTURE_FILTER_NEAREST_WITH_MIPMAPS);
	BIND_ENUM_CONSTANT(DEFAULT_CANVAS_ITEM_TEXTURE_FILTER_MAX);
	BIND_ENUM_CONSTANT(DEFAULT_CANVAS_ITEM_TEXTURE_REPEAT_DISABLED);
	BIND_ENUM_CONSTANT(DEFAULT_CANVAS_ITEM_TEXTURE_REPEAT_ENABLED);
	BIND_ENUM_CONSTANT(DEFAULT_CANVAS_ITEM_TEXTURE_REPEAT_MIRROR);
	BIND_ENUM_CONSTANT(DEFAULT_CANVAS_ITEM_TEXTURE_REPEAT_MAX);
	BIND_ENUM_CONSTANT(SDF_OVERSIZE_100_PERCENT);
	BIND_ENUM_CONSTANT(SDF_OVERSIZE_120_PERCENT);
	BIND_ENUM_CONSTANT(SDF_OVERSIZE_150_PERCENT);
	BIND_ENUM_CONSTANT(SDF_OVERSIZE_200_PERCENT);
	BIND_ENUM_CONSTANT(SDF_OVERSIZE_MAX);
	BIND_ENUM_CONSTANT(SDF_SCALE_100_PERCENT);
	BIND_ENUM_CONSTANT(SDF_SCALE_50_PERCENT);
	BIND_ENUM_CONSTANT(SDF_SCALE_25_PERCENT);
	BIND_ENUM_CONSTANT(SDF_SCALE_MAX);
	BIND_ENUM_CONSTANT(VRS_DISABLED);
	BIND_ENUM_CONSTANT(VRS_TEXTURE);
	BIND_ENUM_CONSTANT(VRS_XR);
	BIND_ENUM_CONSTANT(VRS_MAX);
}
void Viewport::_validate_property(PropertyInfo &p_property) const {