This pull request includes updates to dependencies and configuration
files, upgrading the `uvicorn` package, the current version of which was
causing excessive `ClientDisconnected` errors (see
[here](https://github.com/encode/uvicorn/issues/2271)).

Dependency updates:

* `pyproject.toml`: Upgraded `uvicorn` from `0.28.0` to `0.31.0`. 
* Added `uvicorn-worker` version `0.2.0` as a new dependency.

Configuration updates:

* `Dockerfile`: Updated the `CMD` instruction to use
`uvicorn_worker.UvicornWorker` instead of
`uvicorn.workers.UvicornWorker`, which is
[deprecated](https://www.uvicorn.org/deployment/#gunicorn) starting in
`uvicorn` version
[`0.30.0`](https://github.com/encode/uvicorn/releases/tag/0.30.0).
* `docker-compose.dev.yml`: Modified the `command` for the `srv` service
to use `uvicorn_worker.UvicornWorker` to match the updated worker
dependency.

Breaking changes:
* Because of the deprecated `uvicorn.workers` module, the server task
definitions need to be updated on ECS before deployment.