fix(terraform): update name to region attribute for aws_region

[katapultcloud]

Description

The id attribute of the aws_region data source is deprecated — the AWS
provider now exposes the region name through the dedicated region attribute.

This PR replaces every data.aws_region.<name>[...].id reference with
.region so the module no longer depends on the deprecated attribute and stays
compatible with current AWS provider versions.

This is a drop-in change: region returns the same value the deprecated id
attribute did, so no plan diff or behavioural change is expected.

Type of change

• A bug fix (PR prefix fix)
• A new feature (PR prefix feat)
• A code change that neither fixes a bug nor adds a feature (PR prefix refactor)
• Adding missing tests or correcting existing tests (PR prefix test)
• Changes that do not affect the meaning of the code like white-spaces, formatting, missing semi-colons, etc. (PR prefix style)
• Changes to our CI configuration files and scripts (PR prefix ci)
• Documentation only changes (PR prefix docs)

How Has This Been Tested?

• terraform init and terraform providers lock complete cleanly for the affected modules.
• Pre-commit hooks (terraform_fmt, terraform_validate / tflint, terraform_docs) pass.
• region is a documented drop-in replacement for the deprecated id attribute, so no configuration diff is expected.