dnd_drag_source cannot include any Frames

**Describe the bug**
Using the latest master branch, doing drag n drop operations with a group or anything that instantiates a new Frame, causes a crash. The exception is that you can have one dnd_drag_source that includes multiple Frames, otherwise it will crash when you attempt to drag one.
`egui/crates/egui/src/widget_rect.rs:142:17:
Widget changed layer_id during the frame`

This does not occur in latest release version: `0.27.2`

**To Reproduce**
Steps to reproduce the behavior:
1. Download the Drag and Drop example.
2. Change all `ui.label("__");` to `ui.group(|ui| { ui.label("___"} );`
3. Click to start dragging. Immediate crash.

**Expected behavior**
Drag any widget or widget group.

**Desktop (please complete the following information):**
- OS: Linux (arch, up to date) / Window 10 (22H2)

`0.27.2`
https://github.com/emilk/egui/assets/19319115/00ff2cc5-c118-428b-81c8-393474d42e89

Latest commit: