The code previously used a instances of class GlobalReceiverV2 inheriting QObject in a hash in SignalManager per slot tracking the list of senders to be able to use standard signal/slot connections in Qt. This was a complicated data structure and had issues with cleanups. This has been replaced by using an invoker object based on QtPrivate::QSlotObjectBase which can be passed to QObjectPrivate::connect(const QObject *, int signal, QtPrivate::QSlotObjectBase *, ...). The connections (identified by ConnectionKey) are now stored in a hash with QMetaObject::Connection as value, which can be used to disconnect using QObject::disconnect(QMetaObject::Connection). Deletion tracking is done by using signal QObject::destroyed(QObject*) which requires adapting some tests checking on the connection count and weak ref notification on receivers as was the case before. [ChangeLog][PySide6] Signal connections for Python callables not targeting a QMetaMethod has be reimplemented to simplify code and prepare for removal of the GIL. Task-number: PYSIDE-2810 Task-number: PYSIDE-2221 Change-Id: Ib55e73d4d7bfe6d7a8b7adc3ce3734eac5789bea Reviewed-by: Shyamnath Premnadh <Shyamnath.Premnadh@qt.io> Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>