LibWeb/CSS: Parse mask-clip property

Author: https://github.com/InvalidUsernameException
Commit: f953196cb4
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/5511
Reviewed-by: https://github.com/AtkinsSJ ✅
Reviewed-by: https://github.com/Calme1709

Libraries/LibWeb/CSS/Parser/PropertyParsing.cpp

@@ -664,6 +664,7 @@ Parser::ParseErrorOr<NonnullRefPtr<CSSStyleValue const>> Parser::parse_css_value
         if (auto parsed_value = parse_math_depth_value(tokens); parsed_value && !tokens.has_next_token())
             return parsed_value.release_nonnull();
         return ParseError::SyntaxError;
+    case PropertyID::MaskClip:
     case PropertyID::MaskComposite:
     case PropertyID::MaskMode:
     case PropertyID::MaskOrigin: