Episode images get lost, ongoing reload with gigabytes of mobile data

### Checklist

- [x] I have used the search function for [**OPEN**](https://github.com/AntennaPod/AntennaPod/issues) issues to see if someone else has already submitted the same bug report.
- [x] I have **also** used the search function for [**CLOSED**](https://github.com/AntennaPod/AntennaPod/issues?q=is%3Aissue+is%3Aclosed) issues to see if the problem is already solved and just waiting to be released.
- [x] I will describe the problem with as much detail as possible.
- [x] If the bug only to occurs with a certain podcast, I will include the URL of that podcast.

### App version

3.9.0f

### Android version

Android 13 (iodéOS 4.25)

### Device model

Samsung S9

### First occurred

Several months ago

### Steps to reproduce

Quiet some time ago (several months and some antennapod versions) my quota of mobile data was at the end by beginning of the month, I never had this before.
I can see at system settings that antennapod has used 5 GB of mobile data.
So I changed settings to only update my podcasts manually.
Next month same issue, quota has reached limit at 6th day of month, reason was again antennapod.
Then I changed device settings that antennapod can only use Wifi but not mobile data.
Antennapod now uses no mobile data anymore, but I can see that after one or two days when not connected to Wifi antennapod will "forget" all episode and podcast images. Only grey squares are left at all episodes and podcasts.
When connecting to Wifi then all images will be loaded again.
Next day without Wifi all images are lost again.

I guess there's something wrong with handling of embedded images.
With enabled mobile data I guess images get lost on the fly and are reloaded again and again. So mobile data quota will be eaten by antennapod all the time.

Maybe this is related to #7836, #6755 and #6620

### Expected behaviour

One embedded images are downloaded the should not get lost and downloaded again.

### Current behaviour

_No response_

### Crash logs

_No response_