### Godot version

v4.1.1.stable.official [bd6af8e0e]

### System information

Godot v4.1.1.stable - Ubuntu 22.04.2 LTS 22.04 - Vulkan (Forward+) - integrated Intel(R) UHD Graphics 615 (AML-KBL) () - Intel(R) Core(TM) i3-10100Y CPU @ 1.30GHz (4 Threads)

### Issue description

Summary: When editing the subregion of a StyleBoxTexture, it shows me the entire spritesheet of the Atlas texture, instead of the selected portion of the atlas, making it difficult (and non-intuitive) to correctly select the subregion I need. 

What I expect: I understand that the sub-region may be used to emulate the behavior of a nine-patch. So I would expect to see there the subregion that i selected previously from the Atlas as the texture to be shown.

I have only tested this in a Panel Container

### Steps to reproduce

I found this problem when doing these steps:

- Add a PanelContainer node
- In the inspector select Theme Overrrides -> Style -> new StyleBoxTexture
- In the texture of the StyleBoxTexture select new AtlasTexture
- Dropped the spritesheet in the Atlas of the AtlasTexture
- In Region of the AtlasTexture, selected Edit Region and drew the rectangle on the texture i want:
![image](https://github.com/godotengine/godot/assets/1207326/2e9624b1-63bc-4267-8d7f-59e82df7896e)

- Back in the StyleBoxTexture options, in Sub-Region, clicked on Edit Region to select the nine-patch region i need
- Here is where the region editor shows me the entire spritesheet and not the sub-texture i selected from the atlas. The image below shows the axis correctly positioned for the nine-patch to work, but it is not intuitive because it has to be positioned without seeing the correct texture, making it difficult to finetune for some textures.

![image](https://github.com/godotengine/godot/assets/1207326/a5023afd-7e4b-47c8-adfc-03fda7f6301b)


### Minimal reproduction project

N/A
return Object::cast_to<Sprite2D>(p_object) || Object::cast_to<Sprite3D>(p_object) || Object::cast_to<NinePatchRect>(p_object) || Object::cast_to<StyleBoxTexture>(p_object) || Object::cast_to<AtlasTexture>(p_object);
}
void EditorInspectorPluginTextureRegion::_region_edit(Object *p_object) {
	texture_region_editor->edit(p_object);
}
bool EditorInspectorPluginTextureRegion::parse_property(Object *p_object, const Variant::Type p_type, const String &p_path, const PropertyHint p_hint, const String &p_hint_text, const BitField<PropertyUsageFlags> p_usage, const bool p_wide) {
	if ((p_type == Variant::RECT2 || p_type == Variant::RECT2I)) {
		if (((Object::cast_to<Sprite2D>(p_object) || Object::cast_to<Sprite3D>(p_object) || Object::cast_to<NinePatchRect>(p_object) || Object::cast_to<StyleBoxTexture>(p_object)) && p_path == "region_rect") || (Object::cast_to<AtlasTexture>(p_object) && p_path == "region")) {
			Button *button = EditorInspector::create_inspector_action_button(TTR("Edit Region"));
			button->set_icon(texture_region_editor->get_theme_icon(SNAME("RegionEdit"), SNAME("EditorIcons")));
			button->connect("pressed", callable_mp(this, &EditorInspectorPluginTextureRegion::_region_edit).bind(p_object));
			add_property_editor(p_path, button, true);
		}
	}
	return false; 
}
EditorInspectorPluginTextureRegion::EditorInspectorPluginTextureRegion() {
	texture_region_editor = memnew(TextureRegionEditor);
	EditorNode::get_singleton()->get_gui_base()->add_child(texture_region_editor);
}
TextureRegionEditorPlugin::TextureRegionEditorPlugin() {
	Ref<EditorInspectorPluginTextureRegion> inspector_plugin;
	inspector_plugin.instantiate();
	add_inspector_plugin(inspector_plugin);
}