LibWeb/CSS: Disallow :has() and pseudo-elements in :has() when parsing

Author: https://github.com/AtkinsSJ
Commit: 7f803c5c3d
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2340

Libraries/LibWeb/CSS/Selector.cpp

@@ -687,4 +687,11 @@ SelectorList adapt_nested_relative_selector_list(SelectorList const& selectors)
     return new_list;
 }
 
+// https://drafts.csswg.org/selectors/#has-allowed-pseudo-element
+bool is_has_allowed_pseudo_element(Selector::PseudoElement::Type)
+{
+    // No spec currently defines any pseudo-elements that are allowed in :has()
+    return false;
+}
+
 }