[REG:5.15->6] Shift_JIS support for QDomDocument on Qt6

In Qt6, when an XML document encoded in Shift_JIS is loaded by QDomDocument (setContent()), the following error message is thrown.
"Encoding shift_jis is unsupported".

This issue occurs on Qt6. If we use Qt5, the XML document was read correctly without any error.

Our customers use a lot of code to parse Shift_JIS encoded XML using QDomDocument, so this is a critical issue.

Is there any way to support Shift_JIS in Qt6's QDomDocument?

[Sample XML file and sample code]

Sample XML file : shift-jis.xml

    QDomDocument doc("mydocument");
    QFile file("shift_jis.xml");
    file.open(QIODevice::ReadOnly);

    QString errorMsg;
    int errorLine = -1;
    int errorColumn = -1;

    doc.setContent(&file, &errorMsg, &errorLine, &errorColumn);
    qDebug() << errorMsg;

    file.close();