Add-on Store: Remove invalid cache file (#15111)
Closes #15106
Summary of the issue:
If NVDA has an invalid add-on store cache file it can be safely deleted until a new cache is fetched.
Without deleting it, NVDA will start with an error until it is overwritten by browsing add-ons.
Description of user facing changes
If NVDA has invalid cache data for the add-on store, NVDA will log an exception then delete the invalid cache file.
Description of development approach
If NVDA has invalid cache data for the add-on store, NVDA will log an exception then delete the invalid cache file.
