LibJS: Convert install_error_cause() to ThrowCompletionOr

Author: https://github.com/linusg
Commit: 867b19affb
Pull-request: https://github.com/SerenityOS/serenity/pull/10327
Reviewed-by: https://github.com/IdanHo ✅

Userland/Libraries/LibJS/Runtime/Error.h

@@ -8,6 +8,7 @@
 #pragma once
 
 #include <AK/FlyString.h>
+#include <LibJS/Runtime/Completion.h>
 #include <LibJS/Runtime/Object.h>
 
 namespace JS {
@@ -22,7 +23,7 @@ public:
     explicit Error(Object& prototype);
     virtual ~Error() override = default;
 
-    void install_error_cause(Value options);
+    ThrowCompletionOr<void> install_error_cause(Value options);
 };
 
 // NOTE: Making these inherit from Error is not required by the spec but