avoiding an incorrect ERR_FILE_NOT_FOUND report when the DLL exists but fails to load for another reason

Co-authored-by: bruvzg <7645683+bruvzg@users.noreply.github.com>

core/extension/gdextension_library_loader.cpp

@@ -200,7 +200,10 @@ Error GDExtensionLibraryLoader::open_library(const String &p_path) {
 	// Apple has a complex lookup system which goes beyond looking up the filename, so we try that first.
 	err = OS::get_singleton()->open_dynamic_library(abs_path, library, &data);
 	if (err != OK) {
+#ifdef APPLE_EMBEDDED_ENABLED
 		err = OS::get_singleton()->open_dynamic_library(String(), library, &data);
+#endif
+
 		if (err != OK) {
 			return err;
 		}

platform/windows/os_windows.cpp

@@ -480,12 +480,11 @@ Error OS_Windows::open_dynamic_library(const String &p_path, void *&p_library_ha
 	if (!FileAccess::exists(path)) {
 		//this code exists so gdextension can load .dll files from within the executable path
 		path = get_executable_path().get_base_dir().path_join(p_path.get_file());
+		ERR_FAIL_COND_V(!FileAccess::exists(path), ERR_FILE_NOT_FOUND);
 	}
 	// Path to load from may be different from original if we make copies.
 	String load_path = path;
 
-	ERR_FAIL_COND_V(!FileAccess::exists(path), ERR_FILE_NOT_FOUND);
-
 	// Here we want a copy to be loaded.
 	// This is so the original file isn't locked and can be updated by a compiler.
 	if (p_data != nullptr && p_data->generate_temp_files) {