### 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)
ADD_PROPERTY(PropertyInfo(Variant::BOOL, "use_taa"), "set_use_taa", "is_using_taa");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "use_debanding"), "set_use_debanding", "is_using_debanding");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "use_occlusion_culling"), "set_use_occlusion_culling", "is_using_occlusion_culling");
	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "mesh_lod_threshold", PROPERTY_HINT_RANGE, "0,1024,0.1"), "set_mesh_lod_threshold", "get_mesh_lod_threshold");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "debug_draw", PROPERTY_HINT_ENUM, "Disabled,Unshaded,Lighting,Overdraw,Wireframe"), "set_debug_draw", "get_debug_draw");
#ifndef _3D_DISABLED
	ADD_GROUP("Scaling 3D", "");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "scaling_3d_mode", PROPERTY_HINT_ENUM, "Bilinear (Fastest),FSR 1.0 (Fast)"), "set_scaling_3d_mode", "get_scaling_3d_mode");
	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "scaling_3d_scale", PROPERTY_HINT_RANGE, "0.25,2.0,0.01"), "set_scaling_3d_scale", "get_scaling_3d_scale");
	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "texture_mipmap_bias", PROPERTY_HINT_RANGE, "-2,2,0.001"), "set_texture_mipmap_bias", "get_texture_mipmap_bias");
	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "fsr_sharpness", PROPERTY_HINT_RANGE, "0,2,0.1"), "set_fsr_sharpness", "get_fsr_sharpness");
#endif
	ADD_GROUP("Variable Rate Shading", "vrs_");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "vrs_mode", PROPERTY_HINT_ENUM, "Disabled,Texture,Depth buffer,XR"), "set_vrs_mode", "get_vrs_mode");
	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "vrs_texture", PROPERTY_HINT_RESOURCE_TYPE, "Texture2D"), "set_vrs_texture", "get_vrs_texture");
	ADD_GROUP("Canvas Items", "canvas_item_");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "canvas_item_default_texture_filter", PROPERTY_HINT_ENUM, "Nearest,Linear,Linear Mipmap,Nearest Mipmap"), "set_default_canvas_item_texture_filter", "get_default_canvas_item_texture_filter");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "canvas_item_default_texture_repeat", PROPERTY_HINT_ENUM, "Disabled,Enabled,Mirror"), "set_default_canvas_item_texture_repeat", "get_default_canvas_item_texture_repeat");
	ADD_GROUP("Audio Listener", "audio_listener_");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "audio_listener_enable_2d"), "set_as_audio_listener_2d", "is_audio_listener_2d");
#ifndef _3D_DISABLED
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "audio_listener_enable_3d"), "set_as_audio_listener_3d", "is_audio_listener_3d");
#endif
	ADD_GROUP("Physics", "physics_");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "physics_object_picking"), "set_physics_object_picking", "get_physics_object_picking");
	ADD_GROUP("GUI", "gui_");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "gui_disable_input"), "set_disable_input", "is_input_disabled");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "gui_snap_controls_to_pixels"), "set_snap_controls_to_pixels", "is_snap_controls_to_pixels_enabled");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "gui_embed_subwindows"), "set_embedding_subwindows", "is_embedding_subwindows");
	ADD_GROUP("SDF", "sdf_");