Turn back on Qt support for macOS

Expected behaviour

Qt support is still used on macOS

Actual behaviour

Cocoa support is used so advanced functionality (like zooming) isn't available

Steps to reproduce

• example code pip install opencv-python
• operating system 11.5.2
• architecture (e.g. x86) x86
• opencv-python version 4.5.3.56

Related to #376 and #423

Issue submission checklist

• This is not a generic OpenCV usage question (looking for help for coding, other usage questions, homework etc.)
• I have read the README of this repository and understand that this repository provides only an automated build toolchain for OpenCV Python packages (there is no actual OpenCV code here)
• The issue is related to the build scripts in this repository, to the pre-built binaries or is a feature request (such as "please enable this additional dependency")
• I'm using the latest version of opencv-python

I'd like to help get the Qt support turned back on. Qt 5.15.2 is available now and there were 56 macOS bug fixes in 5.15.1 and then 11 macOS bug fixes in 5.15.2, so I'm hopeful that the issue is resolved and turning back on Qt support would work again

No files or tests are named. Start by tracing the macOS build configuration and Qt dependency handling, then review related issues #376 and #423. Done means Qt support is enabled again for macOS builds and the reported advanced functionality is available.