Qt6.8.0 base fails to compile on msys2 with FEATURE_icu=ON

QT 6.8.0 base fails to compile and fails with unknow symbol to ucalTimeZoneDisplayName

The issue is that the header defines a versiobn with
```
QString ucalTimeZoneDisplayName(UCalendar *ucal,
                                QTimeZone::TimeType timeType,
                                QTimeZone::NameType nameType,
                                const QString &localeCode)
```

and only the cpp implementation only provides a version with

```

QString ucalTimeZoneDisplayName(UCalendar *ucal,
                                QTimeZone::TimeType timeType,
                                QTimeZone::NameType nameType,
                                const QByteArray &localeCode)

```