plugin selection dropdown: header background wrong with dark-mode

[GREEB]

Seems like a dark-mode problem, in light-mode everything seems fine.
(sorry for GIFS hard to screenshot these menus)

Steps to Reproduce:

1. Open Chromium
2. Go to official example Perspective / Movies this should be on @latest
3. Open the plugin selection menu

Expected Result:

The option headers should be the same background as the options like it is in Firefox 103.0.2 (64-bit)

Actual Result:

This happens with Chromium Version 104.0.5112.79, the option headers are not the same background as the options

Environment:

Chromium Version 104.0.5112.79 (Official Build) Arch Linux (64-bit)
Reproduced on: Chromium Version 104.0.5112.101 (Official Build) Pop!_OS 22.04 LTS(64-bit)

Cause

Seems like Chromium does not like to have background-color on top of background, Firefox has no problems with that:

Chrome:

Firefox:

(Firefox doesn't even need the background-color to render the options right, at least on my system)

Fix

This is probably a bad idea but what i found is: when putting background-color underneath background, chromium applies it as expected:

[GREEB]

Issue for this: #1956