Layer deletion collapses all expanded groups

[zstadler]

Maputnik version: main
Browser: Firefox
OS: Windows 11

Description of the bug:
Layer deletion collapses all expanded groups.

Steps to reproduce the behavior:

1. Open "OSM Liberty" style
2. Click "Expand"
3. Delete the background or any other layer
   
4. All the layer groups have collapsed
   

Other than being an anomaly, this behavior also makes it difficult to create example styles for Maplibre issue, as it complicates the process of cleaning-up real-life styles.