### Godot version

4.0beta17

### System information

Linux Mint 21.1

### Issue description

When editing animations for the **frame** property of **Sprite2D**, the preview image does not respect the **region_rect** specified in the Sprite2D's properties.

Godot 4.0 (tested with alpha1 to beta17)
![Screenshot from 2023-02-05 21-19-29](https://user-images.githubusercontent.com/2348534/216868394-45a9dc42-ce4b-4b11-82cb-4491aea46d9b.png)

Godot 3.5
![Screenshot from 2023-02-05 21-19-43](https://user-images.githubusercontent.com/2348534/216868543-cff6eb60-a431-4138-8fa6-5c30a54de0e1.png)

As can be seen in the second screenshot, the region rect is applied to the key preview image in Godot 3.5, but is ignored in Godot 4.0.


### Steps to reproduce

Steps:

1. Set a region rect on a Sprite2D node
2. Add Sprite2D.frame as a track to an AnimationPlayer
3. Insert key
4. Key preview does not take region rect into account

### Minimal reproduction project

[MRP.zip](https://github.com/godotengine/godot/files/10637055/MRP.zip)

Color color = get_animation()->track_get_key_value(get_track(), p_index);
	Ref<Font> font = get_theme_font(SNAME("font"), SNAME("Label"));
	int font_size = get_theme_font_size(SNAME("font_size"), SNAME("Label"));
	int fh = font->get_height(font_size) * 0.8;
	Rect2 rect(Vector2(p_x - fh / 2, int(get_size().height - fh) / 2), Size2(fh, fh));
	draw_rect_clipped(Rect2(rect.position, rect.size / 2), Color(0.4, 0.4, 0.4));
	draw_rect_clipped(Rect2(rect.position + rect.size / 2, rect.size / 2), Color(0.4, 0.4, 0.4));
	draw_rect_clipped(Rect2(rect.position + Vector2(rect.size.x / 2, 0), rect.size / 2), Color(0.6, 0.6, 0.6));
	draw_rect_clipped(Rect2(rect.position + Vector2(0, rect.size.y / 2), rect.size / 2), Color(0.6, 0.6, 0.6));
	draw_rect_clipped(rect, color);
	if (p_selected) {
		Color accent = get_theme_color(SNAME("accent_color"), SNAME("Editor"));
		draw_rect_clipped(rect, accent, false);
	}
}
void AnimationTrackEditAudio::_preview_changed(ObjectID p_which) {