ssh provider has limit to sshtunnel  < 0.2
https://github.com/apache/airflow/blob/9d6ae609b60449bd274c2f96e72486d73ad2b8f9/setup.py#L451

I don't know why? sshtunnel  already released 0.4
I didn't open PR because I don't know this provider i just tried to install it and couldn't due to conflicts with other requirements in my system so eventually i used vitrual env to solve my problem but logging this issue so that someone who knows this code can handle it.
setup.py
'cloudant>=2.0',
]
dask = [
    'cloudpickle>=1.4.1, <1.5.0',
    'dask<2021.3.1;python_version<"3.7"',  
    'dask>=2.9.0, <2021.6.1;python_version>="3.7"',  
    'distributed>=2.11.1, <2.20',
]
databricks = [
    'requests>=2.26.0, <3',
]
datadog = [
    'datadog>=0.14.0',
]
deprecated_api = [
    'requests>=2.26.0',
]
doc = [
    'click>=7.1,<9',
    
    'sphinx>=2.1.2, <3.5.0',
    'sphinx-airflow-theme',
    'sphinx-argparse>=0.1.13',
    'sphinx-autoapi==1.0.0',
    'sphinx-copybutton',
    'sphinx-jinja~=1.1',
    'sphinx-rtd-theme>=0.1.6',
    'sphinxcontrib-httpdomain>=1.7.0',
    'sphinxcontrib-redoc>=1.6.0',
    'sphinxcontrib-spelling==7.2.1',