Description

For YAML translation files we support both the official .yaml extension and the unofficial .yml one.

In #45421 we improved the XLIFF loader to add support for the unofficial .xliff extension in addition to the .xlf official translation.

For QT Translations loader we support files with the .qt extension. But, the official extension for these files, which use the custom TS XML format (see specification) might be .ts. See https://doc.qt.io/qt-5/linguist-programmers.html

Note: before creating a Pull Request to fix this, someone with actual experience in Symfony + QT Translation files should confirm or deny that this is correct. Thanks!