Browser+WebContent+WebDriver: Move Get Page Source to WebContent

Author: https://github.com/trflynn89
Commit: 88dcdf681f
Pull-request: https://github.com/SerenityOS/serenity/pull/16019
Reviewed-by: https://github.com/linusg ✅

Userland/Libraries/LibWebView/OutOfProcessWebView.h

@@ -37,7 +37,6 @@ public:
 
     void debug_request(String const& request, String const& argument = {});
     void get_source();
-    String serialize_source();
 
     void inspect_dom_tree();
     struct DOMNodeProperties {