Graceful shutdown when using the Python worker

#### Is your question related to a specific version? If so, please specify:

The question is not related to a specific version.

#### What binding does your question apply to, if any? (e.g. Blob Trigger, Event Hub Binding, etc)

HTTP trigger

#### Question

The [best practices for Azure Functions](https://learn.microsoft.com/azure/azure-functions/manage-connections?tabs=csharp#static-clients) mention that we should reuse global client instances for better performance with connection pooling. One example also demonstrates the use of [a global Cosmos client instance](https://learn.microsoft.com/en-us/azure/azure-functions/functions-reference-python?tabs=asgi%2Capplication-level&pivots=python-mode-decorators#connect-to-a-database) as a pattern.

However, with these global instances, there should be a way to close the connections on a graceful shutdown, prior to stopping the worker.

Another use-case would be to make sure that all telemetry is flushed before the host is (gracefully) shutting down.

Is there any existing documentation that I missed which would explain how to do this in Python? If not, could you provide guidance on how this should be implemented?