fix(passkeys_doctor): widen device_info_plus constraint to allow ^12.0.0

[M0n7y5]

The device_info_plus constraint in passkeys_doctor is currently pinned to ^11.2.0, which prevents any project that also uses a package requiring device_info_plus ^12.0.0 from upgrading passkeys past 2.8.2.

In my case livekit_client needs device_info_plus ^12.3.0, but any package depending on device_info_plus 12.x would hit the same wall.

The only usage of device_info_plus in passkeys_doctor is DeviceInfoPlugin().iosInfo, which hasn't changed between v11 and v12, so widening the constraint to >=11.2.0 <13.0.0 should be safe.