Meta: Add missing -Wno-unqualified-std-cast-call warning to gn build

Author: https://github.com/ADKaster
Commit: aa1bf3e8a4
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/1515
Reviewed-by: https://github.com/nico
Reviewed-by: https://github.com/trflynn89

Meta/gn/build/BUILD.gn

@@ -129,6 +129,7 @@ config("compiler_defaults") {
       "-Wno-unused-private-field",
       "-Wno-implicit-const-int-float-conversion",
       "-Wno-vla-cxx-extension",
+      "-Wno-unqualified-std-cast-call",
     ]
   } else {
     cflags += [