Fix issue Mapbox used after being disposed

Nobody has claimed this yet.

I have a logout button in my app.
After logging out, an exception is being thrown which says: A MapboxMap was used after being disposed.
Once you have called dispose() on a MapboxMap, it can no longer be used.

Below are the relevant codes:
```
void _showLogoutConfirmationDialogUsing(
BuildContext context,
) =>
ActionDialog.show(
context,
content: context.localize.areYouSureYouWantToLogout,
onActionDismissed: () {
Navigator.of(
context,
).pop();
},
onActionConfirmed: () {
Navigator.of(
context,
).pop();

context.read().add(
const Web3AuthLogoutEvent.logout(),
);
},
);
```

```
@override
void dispose() {
_mapboxMap?.dispose();
_clickedRestriction.dispose();
_centerLocationNotifier.dispose();
_mapStyleNotifier.dispose();

super.dispose();
}
```

https://github.com/user-attachments/assets/b79c8405-ffd2-4216-a27f-681de923c213

Start with the provided logout callback and the widget's dispose() implementation, then reproduce the logout flow while tracing uses of _mapboxMap after disposal. Compare the timing of logout, widget disposal, and map operations; done means the reported "MapboxMap was used after being disposed" exception no longer occurs.

Written by the indexing model from the issue text.