Check if fallback style is already removed (#3715)
Check if fallback style is already removed (#3715)

- Check if the fallback style is already removed and don't add it into the `head` element if it is removed.
- Resolves #3709
- Resolves #3713
darkreader/darkreader,alexanderby/darkreader,darkreader/darkreader,darkreader/darkreader,alexanderby/darkreader,alexanderby/darkreader