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
#
#
#
"""Setup.py for the Airflow project."""
import glob
import logging
import os
import subprocess
import sys
import unittest
from copy import deepcopy
from distutils import log
from os.path import dirname, relpath
from textwrap import wrap
from typing import Dict, List
from setuptools import Command, Distribution, find_namespace_packages, setup
from setuptools.command.develop import develop as develop_orig
from setuptools.command.install import install as install_orig
INSTALL_PROVIDERS_FROM_SOURCES = 'INSTALL_PROVIDERS_FROM_SOURCES'
PY39 = sys.version_info >= (3, 9)
logger = logging.getLogger(__name__)
version = '2.2.0.dev0'
my_dir = dirname(__file__)
def airflow_test_suite() -> unittest.TestSuite:
    """Test suite for Airflow tests"""
    test_loader = unittest.TestLoader()
    test_suite = test_loader.discover(os.path.join(my_dir, 'tests'), pattern='test_*.py')
    return test_suite
class CleanCommand(Command):