Bug 1747423 - Remove the @buttonState* preprocessor vars from .subviewradio controls r=dao

Differential Revision: https://phabricator.services.mozilla.com/D137347

browser/themes/shared/customizableui/panelUI.inc.css

@@ -1521,13 +1521,11 @@ toolbarpaletteitem[place="menu-panel"] > .subviewbutton-nav::after {
   border: 1px solid transparent;
 }
 
-.subviewradio@buttonStateHover@ {
+.subviewradio:hover {
   background-color: var(--button-hover-bgcolor);
 }
 
-.subviewradio[selected],
-.subviewradio[selected]:hover,
-.subviewradio@buttonStateActive@ {
+.subviewradio:is([selected], [selected]:hover, :hover:active) {
   background-color: var(--button-active-bgcolor);
 }