update virtualenv before running tox

Summary:

• update virtualenv to have tox use latest pip
• drop our`==version` pins when its dev to avoid the dependency resolver bug
• move airflow pins that are specific to the version we test in to the test section

Test Plan:
bk
make install_dev_python_modules_verbose

Reviewers: max, jordansanders

Reviewed By: jordansanders

Differential Revision: https://dagster.phacility.com/D8138