Bug 1800828 - Make labels for font dialog not wrap. r=desktop-theme-reviewers,dao

Use max-content sizing for them. This matches the XUL behavior.

Depends on D162342

Differential Revision: https://phabricator.services.mozilla.com/D162343

browser/themes/shared/preferences/preferences.css

@@ -669,7 +669,7 @@ richlistitem[selected] .actionsMenu:focus-visible {
 
 #font-chooser-group {
   display: grid;
-  grid-template-columns: auto 1fr auto auto;
+  grid-template-columns: max-content 1fr max-content max-content;
 }
 
 #defaultFont {