Broker sometimes needs to be restarted for the provider to be reachable again

While testing the new `force_provider_authentication` option, I encountered the issue that the broker would consistently fail to connect to the provider after the network connection had been restored:

```
authd-msentraid[25920]: Could not connect to the provider: Get "https://login.microsoftonline.com/03c73201-ef9e-4182-ae04-0adb51f4a0b6/v2.0/.well-known/openid-configuration": context deadline exceeded. Starting session in offline mode.
```

I repeatedly toggled the network connection on and off in GNOME's system menu but the broker kept failing to connect to the provider. I was able to open the same URL (https://login.microsoftonline.com/03c73201-ef9e-4182-ae04-0adb51f4a0b6/v2.0/.well-known/openid-configuration) in a browser on the same machine.

Restarting the broker via `sudo snap restart authd-msentraid` fixed the issue.

Start by reproducing the failure with force_provider_authentication enabled: toggle the network connection, then inspect the broker's provider connection behavior and the Microsoft login discovery URL shown in the report. Verify that the broker can reconnect after network restoration without requiring sudo snap restart authd-msentraid.

Written by the indexing model from the issue text.