Build fix for PlayStation after r295476

https://bugs.webkit.org/show_bug.cgi?id=241582

Reviewed by Myles C. Maxfield.

In r295476 RenderThemePlayStation::system implementation was removed but the declaration was still
present.

* Source/WebCore/rendering/RenderThemePlayStation.h:

Canonical link: https://commits.webkit.org/251518@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@295513 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/WebCore/rendering/RenderThemePlayStation.h

@@ -33,9 +33,6 @@ namespace WebCore {
 class RenderThemePlayStation final : public RenderTheme {
 public:
     friend NeverDestroyed<RenderThemePlayStation>;
-
-private:
-    FontCascadeDescription systemFont(CSSValueID systemFontID) const final;
 };
 
 } // namespace WebCore