LibWeb: Enable EXPLICIT_SYMBOL_EXPORT

Author: https://github.com/ayeteadoe
Commit: 3df8e00d91
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/5229
Reviewed-by: https://github.com/ADKaster ✅

Libraries/LibWeb/Loader/ProxyMappings.h

@@ -10,10 +10,11 @@
 #include <AK/Vector.h>
 #include <LibCore/Proxy.h>
 #include <LibURL/URL.h>
+#include <LibWeb/Export.h>
 
 namespace Web {
 
-class ProxyMappings {
+class WEB_API ProxyMappings {
 public:
     static ProxyMappings& the();