### 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)

return false;
}
void AnimationTrackEditTypeAudio::draw_key(int p_index, float p_pixels_sec, int p_x, bool p_selected, int p_clip_left, int p_clip_right) {
	Ref<AudioStream> stream = get_animation()->audio_track_get_key_stream(get_track(), p_index);
	if (!stream.is_valid()) {
		AnimationTrackEdit::draw_key(p_index, p_pixels_sec, p_x, p_selected, p_clip_left, p_clip_right);
		return;
	}
	float start_ofs = get_animation()->audio_track_get_key_start_offset(get_track(), p_index);
	float end_ofs = get_animation()->audio_track_get_key_end_offset(get_track(), p_index);
	int px_offset = 0;
	if (len_resizing && p_index == len_resizing_index) {
		float ofs_local = len_resizing_rel / get_timeline()->get_zoom_scale();
		if (len_resizing_start) {
			start_ofs += ofs_local;
			px_offset = ofs_local * p_pixels_sec;
		} else {
			end_ofs -= ofs_local;
		}
	}
	Ref<Font> font = get_theme_font(SNAME("font"), SNAME("Label"));
	int font_size = get_theme_font_size(SNAME("font_size"), SNAME("Label"));
	float fh = int(font->get_height(font_size) * 1.5);
	float len = stream->get_length();
	Ref<AudioStreamPreview> preview = AudioStreamPreviewGenerator::get_singleton()->generate_preview(stream);
	float preview_len = preview->get_length();
	if (len == 0) {
		len = preview_len;