Script fails for new AWS accounts

[alvinsiu]

This is due to a change in AWS security guidelines: https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/concepts-roles.html

This means users will either need to create the aws-elasticbeanstalk-ec2-role manually, or we need to automate this process.

Here's context for creating the role: https://stackoverflow.com/a/76620598/1940450