Can't remove hover effect on items via CSS

**Describe the bug**
I can't figure out how to remove the hover effect on items (see screenshots below).

I thought I could achieve this with the configuration option `hover_item_css` in `copyq.conf`, but setting it to `""`, `"\n ;background: transparent"` or even `"\n ;color: #f0f"` (for testing purposes) does not change anything visually. Maybe I just don't understand what that option is supposed to change in the first place.

**To Reproduce**
Steps to reproduce the behavior:
1. Modify `hover_item_css` in `copyq.conf`
2. Try to observe the change visually

**Expected behavior**
I would expect to be able to change the CSS applied to items on hover with `hover_item_css`, in my case to just remove any hover effect.

**Screenshots (of hover effect)**
When hovering over non-selected item:
When hovering over selected item:

**Version, OS and Environment**
- Application Version: 7.1.0 ([Nixpkg from 23.11 channel](https://github.com/NixOS/nixpkgs/blob/nixos-23.11/pkgs/applications/misc/copyq/default.nix))
- Qt Version: 6.6.1
- Compiler: GCC
- Arch: x86_64-little_endian-lp64
- OS: NixOS 23.11 (Tapir)
- Wayland Compositor: Hyprland

**Additional context**
[My CopyQ config as of writing this](https://github.com/julius-boettger/dotfiles/blob/e1ac24d7140ab712b190f1b631b6571fdd201332/copyq.conf)