[BUG] Intermittent demultiplexer stopped error messages in container shutdown

[raymondchen625]

Agent Environment

agent 7.50.3 on AWS ECS

Describe what happened:
When a Datadog agent container shuts down, there is intermittent error logs like:

2024-02-12 12:36:22.853,2024-02-12 12:36:22 UTC | CORE | ERROR | (pkg/collector/worker/worker.go:163 in Run) | Error getting default sender: demultiplexer is stopped. Not sending status check for container_image,datadog-ecs/datadog-agent/28911fcab7c646588c0b7b92a6e41ef6,123456789012:redacted-cluster

This shows up after the shutdown signal log: Caught signal ‘terminated'; terminating..

Describe what you expected:
The error message should not be seen or the level should be warn in the case of container shutting down.

Steps to reproduce the issue:

The logs show up intermittently during container shutdown.

Additional environment details (Operating System, Cloud provider, etc):
Datdog agent container running on AWS ECS as a daemon service