When you install Aiflow with an extra, the required provider packages should be installed automatically.

For example:

`pip instal apache-airflow[google]` should install apache-airlfow-providers-google package.
setup.py
packages=packages_to_install,
        package_data={
            'airflow': ['py.typed'],
            '': [
                'airflow/alembic.ini',
                "airflow/git_version",
                "*.ipynb",
                "airflow/providers/cncf/kubernetes/example_dags/*.yaml",
            ],
            'airflow.api_connexion.openapi': ['*.yaml'],
            'airflow.serialization': ["*.json"],
        },
        include_package_data=True,
        zip_safe=False,
        entry_points={
            "console_scripts": [
                "airflow = airflow.__main__:main",
            ],
        },
        install_requires=INSTALL_REQUIREMENTS,
        setup_requires=[
            'bowler',
            'docutils',
            'gitpython',
            'setuptools',
            'wheel',
        ],
        extras_require=EXTRAS_REQUIREMENTS,
        classifiers=[
            'Development Status :: 5 - Production/Stable',