Allow commercial license on Qt6

[miurahr]

Is your feature request related to a problem? Please describe.

In Qt 5, aqt update configuration to select open-source licenses. Qt 6 removes a configuraition to select whether commercial or open-source license. Here is a document: https://doc.qt.io/qt-6/qt6-buildsystem.html#selecting-a-qt-license

A option -opensource, -commercial, and -confirm-license are ignored in Qt 6, and will be removed in future versions.

Describe the solution you'd like

Aqt does not adjust license configuration on Qt6 and later.

Describe alternatives you've considered

Alternatively we can add option --no-update-license to change behavior.

Additional context

[miurahr]

Here is a place we can update to call updater.set_license only when handle Qt5.

https://github.com/miurahr/aqtinstall/blob/master/aqt/updater.py#L290

updater.set_license(base_dir, version_dir, arch_dir)