switch to hypercorn to reduce memory leak

[vincentsarago]

This PR change the ASGI web server for the STAC and Raster API to use Hypercorn instead of Uvicorn.

In fastapi/fastapi#1624 people mention that it resolved their issue. I've run a small tiler locally (simple titiler app) and confirmed that the memory growth was way more stable when using Hypercorn

[mmcfarland]

I did some memory testing with a single process here too, against a uvicorn and hypercorn images as well as with and without our experimental malloc env var. In general, hypercorn with the flag was had the lowest rate of increase, but only marginally. The presence of the malloc flag still has an outsized impact in our scenario. If you see more stable consumption in a default titiler deployment, I'm inclined to merge this and evaluate in staging. In the dev environment, there wasn't a difference in workflow (hot reloading, etc)

[mmcfarland]

I think the uvicorn dep can be removed here and in stac setup if the commands in docker-compose are similarly changed to

command: >
      bash -c "pypgstac pgready && hypercorn pcstac.main:app --bind 0.0.0.0:8081 --reload"

and

command: [ "hypercorn", "pctiler.main:app", "--bind", "0.0.0.0:8082", "--reload"  ]

[vincentsarago]

In general, hypercorn with the flag was had the lowest rate of increase, but only marginally.

👍 no need of hypercorn then!