The IPs used for the hosted Agent IP ranges are linked through here. I have not had much success using it for hosted agents. The list is big and the documentation is not really clear about what types of services you need to whitelist.
I would go with whitelisting the hosted agent IP just-in-time during the pipeline run, then remove it as a final step. First you can grab the ip of the hosted agent:
$hostedIPAddress = Invoke-RestMethod http://ipinfo.io/json | Select -exp ip
Then you could use the AWS CLI or AWS PowerShell module to add the specific IP. Azure DevOps AWS tools task includes the CLI.
Do the needed work against the DB, then make sure you clean up the rule\temp security group at the end.