Support Terraform 1.0

[dav3r]

🗣 Description

This PR moves this skeleton from Terraform 0.14 to 1.0.

💭 Motivation and context

This is the last step in our journey of migrating Terraform to a current 1.0.x version. We previously upgraded from Terraform 0.12 to 0.13 with #82 and from 0.13 to 0.14 with #86.

This PR is a part of cisagov/cool-system#219 and related to cisagov/setup-env-github-action#41.

This PR is similar to cisagov/skeleton-tf-module#64 and cisagov/skeleton-ansible-role-with-test-user#29.

When all testing has been completed with Terraform 1.0 and cisagov/setup-env-github-action#41 has been merged, 1075951 will be reverted in a new pull request.

🧪 Testing

To test this PR, I installed Terraform 1.0.7 on my local system and validated the following:

• All pre-commit tests pass locally
• All GitHub actions pass for this PR
• I was able to successfully terraform apply without any errors in all workspaces of the terraform-build-user/ and terraform-post-packer/ directories

✅ Checklist

• This PR has an informative and human-readable title.
• Changes are limited to a single goal - eschew scope creep!
• All relevant type-of-change labels have been added.
• I have read the CONTRIBUTING document.
• These code changes follow cisagov code standards.
• All relevant repo and/or project documentation has been updated to reflect the changes in this PR.
• All new and existing tests pass.

[mcdonnnj]