Folder maintains old podcast image after artwork refresh [Version 8.12-rc-1 (9428)]

### Description

Podcast has updated artwork. Refreshed on the podcast details screen, but it shows incorrectly on the main screen with folders.

### Step-by-step reproduction instructions

1. Update podcast artwork
2. Return to main screen -> wrong artwork shown

### Screenshots or screen recording

New artwork:

Folder showing old artwork:

### Did you search for existing bug reports?

- [x] I have searched for existing bug reports.

### Device, Operating system, and Pocket Casts app version

_No response_

Reproduce the issue by updating podcast artwork on the podcast details screen, then returning to the main screen and checking the folder artwork. Trace how the refreshed artwork reaches the folder view; done means the folder shows the new artwork without requiring additional refreshes.

Written by the indexing model from the issue text.