Theme selection breaks when switching themes in multiple windows

[ehuss]

Problem

When switching themes with multiple windows open, it seems to get confused and has multiple themes selected simultaneously, causing rendering issues.

Steps

1. Open https://rust-lang.github.io/mdBook/ in window A. Select light theme.
2. Open https://rust-lang.github.io/mdBook/ in window B. Should be currently in the light theme.
3. In window A, choose Ayu theme.
4. In window B, choose Ayu theme.
5. Notice that B doesn't switch themes.

Possible Solution(s)

No response

Notes

No response

Version

0.4.47