fix: bg in dark mode hover state for hide counts button

[yardensachs]

Fixes #1303

[lukasvinclav]

Thanks for the PR. I just checked the functionality on the demo site and it works correctly for me:

http://localhost:8000/en/admin/formula/driverwithfilters/

Would you mind testing it? Please refresh the local cache before test. Thanks

[yardensachs]

@lukasvinclav I was trying this one:
https://demo.unfoldadmin.com/en/admin/formula/driverwithfilters/?_facets=True

You need to click on show counts first, and its only an issue with Hide Counts button

[lukasvinclav]

Thanks for the PR. I checked the code and I noticed the trick was removing wrong background color:

#1314