### Godot version

v4.2.dev.custom_build [0c2144da9]

### System information

Debian Linux X11 Xfce

### Issue description

Prerequisite: Be in Single Window Mode in the Editor
The Filesystem Dock is unusable when it is floating, which is not expected.
It appears garbled in the top-left corner:
![image](https://github.com/godotengine/godot/assets/6299227/109f7922-97de-44c3-814a-ca7f970e0602)

The following errors are shown:
```
  editor/window_wrapper.cpp:220 - Condition "!is_window_available()" is true.
  editor/window_wrapper.cpp:202 - Condition "!get_window_enabled()" is true. Returning: Rect2i()
  editor/window_wrapper.cpp:207 - Condition "!get_window_enabled()" is true. Returning: -1
  editor/window_wrapper.cpp:207 - Condition "!get_window_enabled()" is true. Returning: -1
```

bisecting lead to #62378
possibly related to #44439

### Steps to reproduce

1. Start a project in the Editor
2. Switch to Single Window Mode in the Editor and reload (if necessary)
3. Make the Filesystem Dock floating

### Minimal reproduction project

Editor issue
} else if (ED_IS_SHORTCUT("editor/editor_prev", p_event)) {
			_editor_select_prev();
		} else if (ED_IS_SHORTCUT("editor/command_palette", p_event)) {
			_open_command_palette();
		} else {
		}
		if (old_editor != editor_plugin_screen) {
			get_tree()->get_root()->set_input_as_handled();
		}
	}
}
void EditorNode::_update_from_settings() {
	int current_filter = GLOBAL_GET("rendering/textures/canvas_textures/default_texture_filter");
	if (current_filter != scene_root->get_default_canvas_item_texture_filter()) {
		Viewport::DefaultCanvasItemTextureFilter tf = (Viewport::DefaultCanvasItemTextureFilter)current_filter;
		scene_root->set_default_canvas_item_texture_filter(tf);
	}
	int current_repeat = GLOBAL_GET("rendering/textures/canvas_textures/default_texture_repeat");
	if (current_repeat != scene_root->get_default_canvas_item_texture_repeat()) {
		Viewport::DefaultCanvasItemTextureRepeat tr = (Viewport::DefaultCanvasItemTextureRepeat)current_repeat;
		scene_root->set_default_canvas_item_texture_repeat(tr);
	}
	RS::DOFBokehShape dof_shape = RS::DOFBokehShape(int(GLOBAL_GET("rendering/camera/depth_of_field/depth_of_field_bokeh_shape")));
	RS::get_singleton()->camera_attributes_set_dof_blur_bokeh_shape(dof_shape);
	RS::DOFBlurQuality dof_quality = RS::DOFBlurQuality(int(GLOBAL_GET("rendering/camera/depth_of_field/depth_of_field_bokeh_quality")));
	bool dof_jitter = GLOBAL_GET("rendering/camera/depth_of_field/depth_of_field_use_jitter");
	RS::get_singleton()->camera_attributes_set_dof_blur_quality(dof_quality, dof_jitter);
	RS::get_singleton()->environment_set_ssao_quality(RS::EnvironmentSSAOQuality(int(GLOBAL_GET("rendering/environment/ssao/quality"))), GLOBAL_GET("rendering/environment/ssao/half_size"), GLOBAL_GET("rendering/environment/ssao/adaptive_target"), GLOBAL_GET("rendering/environment/ssao/blur_passes"), GLOBAL_GET("rendering/environment/ssao/fadeout_from"), GLOBAL_GET("rendering/environment/ssao/fadeout_to"));
	RS::get_singleton()->screen_space_roughness_limiter_set_active(GLOBAL_GET("rendering/anti_aliasing/screen_space_roughness_limiter/enabled"), GLOBAL_GET("rendering/anti_aliasing/screen_space_roughness_limiter/amount"), GLOBAL_GET("rendering/anti_aliasing/screen_space_roughness_limiter/limit"));
	bool glow_bicubic = int(GLOBAL_GET("rendering/environment/glow/upscale_mode")) > 0;