Cannot download episodes when an invalid storage location is set

### Description

A user reported that after copying the app from one phone to another, their sd card storage selection was included in the transfer, and that caused Pocket Casts to "fail" every download because the new phone did not have an sd card slot.

> I was having trouble for a bit trying to download podcast episodes. They would seem to download but then immediately go back to the "download queued" status and retry. Eventually they would just fail. Streaming the episodes were no problem though....
>
> I checked my "Storage & data usage" settings and saw that the Storage location was set to "SD Card". I thought that was odd because my Samsung S23 does not have an SD card slot. I flipped Storage to "Phone" and then downloads were finally successful.
>
> I got and switched to this S23 phone recently. I realized this "SD Card" storage location setting carried over from my old Samsung phone when I migrated all my apps and settings (using Samsung Smart Switch). So it was still trying to save to the "SD Card" I specified on my old phone.
>
> ...Maybe a check could be added to validate the Storage location? It seems it's common for manufactures to stop adding expandable storage to newer models.

6006283-zd-woothemes

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

Samsung S23

Start by reproducing the Samsung S23 scenario with Storage location set to SD Card on a device without an SD card, then trace the storage-location handling and download retry path. Done means an invalid migrated location is detected and downloads no longer repeatedly queue or fail without requiring manual correction.

Written by the indexing model from the issue text.