Investigate video memory leaks on Win11.

[Mysticial]

Probably nothing we can do about this right now. Just putting it up for the record.

[Mysticial]

Reproducible on my laptop.

Basically the leak starts the moment the view finder is set:

m_camera->setViewfinder(m_camera_view);

Furthermore, this is an actual leak that doesn't get freed when the both the QCamera or the QCameraViewFinder are destroyed. Thus, this is an unrecoverable leak.

So far, the only way to avoid this leak in code is to not use QCameraViewFinder and manage the rendering ourselves. We do have an incomplete implementation of this, but it's far too slow since the QVideoFrames coming from the capture card are JPG and Qt's JPG decoder is far too slow. Really, this should be GPU rendered.

So rather than trying to optimize the software rendering, we're gonna attack this from two angles:

1. See if migrating to Qt6 will fix this.
2. See if we can use OpenCV instead.

[Mysticial]

Fixed by moving to Qt6.