Move to version 3.x of the AWS Terraform provider

[dav3r]

🗣 Description

This pull request upgrades the Terraform code to use to version 3 of the Terraform AWS provider.

💭 Motivation and Context

Version 3 of the AWS provider has been out for a while. We don't want to get left behind.

🧪 Testing

• For terraform-build-user, I successfully ran terraform apply and confirmed that the build-skeleton-packer user was properly destroyed and then re-created (there have been some significant Terraform changes since that user was initially created, so this was expected).
• For terraform-post-packer, I successfully ran terraform apply in both Staging and Production Terraform workspaces. I then ran terraform destroy in the Production workspace, since I don't think there's any real Production need for those permissions to the skeleton-packer AMI (if there is, they can easily be restored later).
• All pre-commit hooks pass.

📷 Screenshots (if appropriate)

🚥 Types of Changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (causes existing functionality to change)
• Provider upgrade

✅ Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[jsf9k]

Yes!

[mcdonnnj]

Onward and upward!

[hillaryj]

🦖

[felddy]

Holy cannoli! I can't believe me eyes! 👀