LibWeb: Make CanvasGradient GC-allocated

Author: https://github.com/awesomekling
Commit: 0d2fee351a
Pull-request: https://github.com/SerenityOS/serenity/pull/14816
Reviewed-by: https://github.com/ADKaster
Reviewed-by: https://github.com/linusg ✅

Userland/Libraries/LibWeb/Forward.h

@@ -449,7 +449,6 @@ class URLSearchParamsIterator;
 
 namespace Web::Bindings {
 class BlobWrapper;
-class CanvasGradientWrapper;
 class CryptoWrapper;
 class DOMExceptionWrapper;
 class DOMPointWrapper;