pip wheel . --verbose didn't build a wheel for opencv, just opencv_contrib and numpy

Expected behaviour

Build a .whl file for opencv as well as one for opencv_contrib

Actual behaviour

.whl for opencv_contrib was built but .whl file for opencv was not built

Steps to reproduce

export ENABLE_CONTRIB=1

ubuntu 22.04 on WSL2

x86-64

• opencv-python version
  did git checkout tag/4.5.5 in the opencv_contrib subdirectory
  did git checkout tag/4.5.5 in the opencv subdirectory

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

Start by reproducing pip wheel . --verbose with ENABLE_CONTRIB=1 on the reported Ubuntu 22.04 WSL2 x86-64 setup, using the OpenCV and opencv_contrib 4.5.5 checkouts. Inspect the repository's build scripts to determine why only opencv_contrib and numpy wheels are produced; done means the command builds an opencv wheel as well.