file(ARCHIVE_CREATE) doesn't allow specifying the compression level
Qt is using a perl / Powershell script to create a gzip / zstd archive from
freedesktop.org.xml then save if as a byte blob in a cpp file.
At https://codereview.qt-project.org/c/qt/qtbase/+/311114 I'm using
file(ARCHIVE_CREATE) to replace the perl / Powershell script.
As it turns out the perl / Powershell scripts are setting the highest compression levels in order to make the smallest archive possible.
file(ARCHIVE_CREATE) I cannot do the same. The interface is not supporting it.