`default-branch-button` - Duplicated after system theme update

[fregante]

Description

I'm not sure if we can prevent this effectively, due to how React works 😩

I think a lot of features are affected, not just this one.

How to replicate the issue + URL

1. Use latest preview
2. https://github.com/refined-github/refined-github/tree/esbuild-2
3. Toggle system color

Extension version

23.11.15

Browser(s) used

Chrome