Windows: Duplicated icon in notification/status area

- [x] I am on the [latest](https://github.com/ActivityWatch/activitywatch/releases/latest) ActivityWatch version.
- [x] I have searched the issues of this repo and believe that this is not a duplicate.

- **OS name and version**: Microsoft Windows 10
- **ActivityWatch version**: 0.12.2

## Describe the bug
I have been getting 2 icons for ActivityWatch in Windows' taskbar's notification area (aka "system tray") for a while. Both are usable, and offer "Quit ActivityWatch", which gets rid of one of them, but not the other. However, the duplication comes back every time Windows is restarted.

I am 99% confident that this started the last time I upgraded ActivityWatch. I went from 0.12.0 to 0.12.2. So while I did not verify, there are good chances that installing 0.12.0 then installing 0.12.2 would suffice to reproduce.