I fired up my raspberry and checked the versions. The Python version on your bookworm should be 3.11 and with apt you can install pyqt 5.15.9 which then can be use in your venv using the '--system-site-packages' option. I had to adapt my own projects to the provided versions of raspberry environments so I would not have to deal with those issues.

I believe part of the reason this happens, is piwheels that is used by your raspberry.

piwheels.org states, that pyqt5 will fail to build in bookworm

Source: https://www.piwheels.org/project/pyqt5/

Maybe you could try to install another distro like Ubuntu 24.04 on your raspi, this might work.