### Godot version

v4.0.beta.custom_build [eaf306e0b]

### System information

Windows 10

### Issue description

Selecting a `Window` node in the Editor's SceneTree results in the message
```
editor/editor_data.cpp:1058 - Parameter "p_node" is null.
```
and the Inspector shows empty content instead of the Window's properties.

I would expect, that clicking on a node in the SceneTree lets me edit the properties of the node.

Bisecting shows that this behavior got introduced in #71770

### Steps to reproduce

1. Create a Window node
2. Click on the Window node in the Editor's SceneTree

### Minimal reproduction project

N/A
} else {
						grid_color = cell % primary_grid_steps == 0 ? primary_grid_color : secondary_grid_color;
					}
					viewport->draw_line(Point2(i, 0), Point2(i, viewport_size.height), grid_color, Math::round(EDSCALE));
				}
				last_cell = cell;
			}
		}
		if (grid_step.y != 0) {
			for (int i = 0; i < viewport_size.height; i++) {
				const int cell =
						Math::fast_ftoi(Math::floor((xform.xform(Vector2(0, i)).y - real_grid_offset.y) / (grid_step.y * Math::pow(2.0, grid_step_multiplier))));
				if (i == 0) {
					last_cell = cell;
				}
				if (last_cell != cell) {
					Color grid_color;
					if (primary_grid_steps == 0) {
						grid_color = secondary_grid_color;
					} else {
						grid_color = cell % primary_grid_steps == 0 ? primary_grid_color : secondary_grid_color;
					}
					viewport->draw_line(Point2(0, i), Point2(viewport_size.width, i), grid_color, Math::round(EDSCALE));
				}
				last_cell = cell;
			}
		}
	}
}
void CanvasItemEditor::_draw_ruler_tool() {