CISA KEV Script missing retry logic for list asset groups request

[jaredkalmus]

For this script: https://github.com/KennaSecurity/blog_samples/blob/main/python/cisa_risk_meter/build_cisa_risk_meter.py

There is no retry logic for the section of the script that lists out the risk meters. This endpoint can have poor performance for customers who have a lot of risk meters, and the entire script will fail if one 504 error is returned. Adding retry logic like the script has for the list CVE section could be a big help in avoiding script execution errors.