### 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
err = platform->export_pack(export_preset, export_defer.debug, export_path);
					}
				} else { 
					String config_error;
					bool missing_templates;
					if (!platform->can_export(export_preset, config_error, missing_templates, export_defer.debug)) {
						ERR_PRINT(vformat("Cannot export project with preset \"%s\" due to configuration errors:\n%s", preset_name, config_error));
						err = missing_templates ? ERR_FILE_NOT_FOUND : ERR_UNCONFIGURED;
					} else {
						platform->clear_messages();
						err = platform->export_project(export_preset, export_defer.debug, export_path);
					}
				}
				if (err != OK) {
					export_error = vformat("Project export for preset \"%s\" failed.", preset_name);
				} else if (platform->get_worst_message_type() >= EditorExportPlatform::EXPORT_MESSAGE_WARNING) {
					export_error = vformat("Project export for preset \"%s\" completed with warnings.", preset_name);
				}
			}
		}
		if (err != OK) {
			ERR_PRINT(export_error);
			_exit_editor(EXIT_FAILURE);
		} else if (!export_error.is_empty()) {
			WARN_PRINT(export_error);
		}
		_exit_editor(EXIT_SUCCESS);
	}
}
void EditorNode::_resources_reimported(const Vector<String> &p_resources) {