set tcp_keepalive=True for the boto3 s3 client

this seems like a smart thing to do anyway, even though the connection
issues that are motivating the retries are on the zoom side.

See: https://www.miketheman.net/2022/10/04/reduce-aws-lambda-latencies-with-keep-alive-in-python/

functions/zoom-downloader.py

@@ -17,6 +17,7 @@
 import logging
 import concurrent.futures
 from copy import deepcopy
+from botocore.config import Config
 from tenacity import (
     Retrying,
     RetryError,
@@ -57,7 +58,7 @@ class ZoomDownloadLinkError(Exception):
 
 
 sqs = boto3.resource("sqs")
-s3 = boto3.client("s3")
+s3 = boto3.client("s3", config=Config(tcp_keepalive=True))
 
 
 @setup_logging
@@ -368,6 +369,7 @@ def upload_to_s3(self):
         for file in self.recording_files:
             try:
                 retry_attempts = Retrying(
+                    reraise=True,
                     stop=stop_after_attempt(STREAM_FROM_ZOOM_TO_S3_RETRIES),
                     wait=wait_fixed(STREAM_FROM_ZOOM_TO_S3_RETRY_WAIT),
                     retry=retry_if_exception_type(RetryableDownloadError),