Undo recent changes related to Python upgrade

This changeset undoes the recent changes we tried after the Python 3.13 update as they had no bearing on the SSL cert validation errors.  Back to the drawing board!

Signed-off-by: Carlo Costino <carlo.costino@gsa.gov>

app/celery/tasks.py

@@ -1,6 +1,6 @@
 import json
-import time
 
+import gevent
 from celery.signals import task_postrun
 from flask import current_app
 from requests import HTTPError, RequestException, request
@@ -84,7 +84,7 @@ def process_job(job_id, sender_id=None):
         process_row(row, template, job, service, sender_id=sender_id)
         count = count + 1
         if count % 3 == 0:
-            time.sleep(1)
+            gevent.sleep(1)
 
     # End point/Exit point for message send flow.
     job_complete(job, start=start)