Building wheel taking an extremely long time

Expected behaviour

For it to install quickly.

Actual behaviour

If you run pip3 install opencv-python the installation appears to get stuck at Building wheel for opencv-python. I left it for about an hour with no visible progress.
I've since run pip3 install opencv-python --verbose and as of writing I'm an hour in at 28%.

Steps to reproduce

• See above
• Raspberry Pi OS Bullseye
• ARM
• 4.8.1.78

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

Reproduce pip3 install opencv-python --verbose on Raspberry Pi OS Bullseye with ARM and version 4.8.1.78, then review the build output to identify where the wheel build spends its time. Done should mean determining whether the delay is expected or identifying a build-toolchain change that measurably improves installation time.