[SYNPY-1533] Lower the HTTPX connection limit to 5

[BryanFauble]

https://sagebionetworks.jira.com/browse/SYNPY-1533

Problem:

1. Found in this service desk ticket: https://sagebionetworks.jira.com/browse/SYNSD-1233 a collaborator was having issues uploading files for connection/read failures during the upload process.
2. The default HTTPX library max_connections is 100, for non-storage operations I originally lowered this to 25 as I found this to not affect any performed. This has been further lowered to 5.

Solution:

1. Lower max_connections to 5 for both storage operations (Like connecting to S3) and Synapse operations (REST API servers)

Testing:

1. We will need to test on a flaky connection as well as re-run a portion of the download/upload benchmarking to assess performance of the change.