PyQt: Update to latest versions

PyQt5:

• devel/py-qt5-pyqt: Update to 5.15.11
• graphics/py-qt5-3d: Add port
• net/py-qt5-networkauth: Update to 5.15.6
• www/py-qt5-webengine: Update to 5.15.7
• x11-toolkits/py-qt5-chart: Update to 5.15.7
• x11-toolkits/py-qt5-datavis3d: Add port

PyQt6:

• devel/py-qt6-pyqt: Update to 6.7.1

Build tools:

• devel/sip: Update to 6.8.6
• devel/py-qt5-sip: Update to 12.15.0
• devel/py-qt6-sip: Update to 13.8.0
• devel/py-qtbuilder: Update to 1.16.4

The build tools are now all licensed BSD2CLAUSE and have been converted
to PEP517.