Background fetch causes freeze for roughly a second

[jesseduffield]

Describe the bug
If you set this in your config:

refresher:
    fetchInterval: 1

And then just navigate around lazygit e.g. navigating through the list of commits, you'll notice just how frequently lazygit pauses as part of a fetch, blocking the UI thread. This is super annoying!

The background fetch should not have this big of an impact on the UI