add env var for number of nginx unit worker processes
i suspect that with asgi we'll be better off with 1 instead of 4 worker
processes - i'd like us to be able to test this per deployment via an
env var
Reduce nginx unit request limit to 7.5k
50k was very high, taking over 5 hours even at busy times to reach this
Reduce it to 7.5k which should stop our memory usage creeping up constantly
when we aren't deploying
allow asgi/wsgi to be configurable by env var
This will let us roll out asgi separate across services as we had
issues with our recordings capture pods on asgi
