Macos build with Qt5

[paskino]

On Macos the presence of both Qt5 and Qt6 in the environment lead to an error:

objc[72053]: Class QT_ROOT_LEVEL_POOL__THESE_OBJECTS_WILL_BE_RELEASED_WHEN_QAPP_GOES_OUT_OF_SCOPE is implemented in both /Users/Brian/miniconda3/envs/idvc_environment/lib/libQt6Core.6.11.2.dylib (0x133315728) and /Users/Brian/miniconda3/envs/idvc_environment/lib/libQt5Core.5.15.15.dylib (0x161fd12f8). One of the two will be used. Which one is undefined.

objc[72053]: Class KeyValueObserver is implemented in both /Users/Brian/miniconda3/envs/idvc_environment/lib/libQt6Core.6.11.2.dylib (0x133315750) and /Users/Brian/miniconda3/envs/idvc_environment/lib/libQt5Core.5.15.15.dylib (0x161fd1320). One of the two will be used. Which one is undefined.

objc[72053]: Class RunLoopModeTracker is implemented in both /Users/Brian/miniconda3/envs/idvc_environment/lib/libQt6Core.6.11.2.dylib (0x1333157a0) and /Users/Brian/miniconda3/envs/idvc_environment/lib/libQt5Core.5.15.15.dylib (0x161fd1370). One of the two will be used. Which one is undefined.

Segmentation fault: 11

This PR removes the issue by forcing Qt5.