build wheels for opencv-python, which is required to install pyproject.toml-based projects

To build wheels for `opencv-python` and install pyproject.toml-based projects, you can follow these steps:

1. Install the necessary tools:
- Make sure you have Python and pip installed on your system.
- Install `build-essential` package if you are on a Linux system, or Xcode Command Line Tools if you are on macOS.
- Install `CMake` if it's not already installed.

2. Clone the `opencv-python` repository:

   git clone https://github.com/skvark/opencv-python.git

3. Navigate to the cloned repository:

   cd opencv-python

4. Install the required dependencies:

   pip install -r requirements-dev.txt

5. Build the wheel:

   python -m build

6. The built wheel file(s) will be generated in the `dist` directory.

You can then install the built `opencv-python` wheel using pip like any other package:

pip install opencv-python-X.X.X-cpXX-cpXXm-PLATFORM.whl

Replace `X.X.X` with the specific version number obtained from the built wheel file, and `PLATFORM` with your system platform (e.g., `win_amd64`, `macosx_10_15_x86_64`, `manylinux1_x86_64`, etc.).

Please note that building wheels for `opencv-python` requires some dependencies to be installed on your system. If you encounter any issues during the build process, make sure you have installed all the necessary dependencies as mentioned in the repository's documentation.