* Replace foreach
* Replace QRegExp with QRegularExpression
* Replace QApplication::fontMetrics
* Replace QColor::isValidColor
* Replace canConvert(QVariant)
* Replace QString::midRef and QCharRef
* Add TODO for replacing QDesktopWidget for Qt 6
* Add TODO for replacing QTextCodec for Qt 6
* Fix QWidget::enterEvent for Qt 6
* qRegisterMetaTypeStreamOperators done automatically in Qt 6
* Fix QWidget::mapToGlobal for Qt 6
* Migrate QDesktopWidget replacement from old qt6 branch
* Drop Qt 5 support
closes: #1374 .
Use SPDX short-form identifiers instead of lengthy copyright
header to document per-file license and copyright.
This commit updates all files under src/ directory where applicable
as well as org.flameshot.Flameshot.metainfo.xml.
