LibWeb: Skip dynamic_cast in CSSRGB after we already did a type check

Author: https://github.com/awesomekling
Commit: https://github.com/LadybirdBrowser/ladybird/commit/57809b11003
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/4395

Libraries/LibWeb/CSS/StyleValues/CSSRGB.cpp

@@ -67,7 +67,7 @@ bool CSSRGB::equals(CSSStyleValue const& other) const
     auto const& other_color = other.as_color();
     if (color_type() != other_color.color_type())
         return false;
-    auto const& other_rgb = as<CSSRGB>(other_color);
+    auto const& other_rgb = static_cast<CSSRGB const&>(other_color);
     return m_properties == other_rgb.m_properties;
 }