UTF-8 is the new default for QTextStream.

src/qtresourcetemplateloader.cpp

@@ -29,7 +29,9 @@ Grantlee::Template QtResourceTemplateLoader::loadByName(const QString &fileName,
         }
 
         QTextStream fstream(&file);
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
         fstream.setCodec("UTF-8");
+#endif
         const auto fileContent = fstream.readAll();
 
         return engine->newTemplate(fileContent, fileName);