Notifications are not allowed for this application

This error is displayed when we try showing a [toast notification](https://github.com/wakatime/macos-wakatime/blob/b0225ffa13a74f1ec40c779ec5fa46e3d8593fd5/WakaTime/AppDelegate.swift#L206). Not sure why, it was working before so we should start by looking for the release that broke notifications.