feat: implement the new iam interface in artifact-registry

[NitriKx]

This PR implements the new IAM interface in the atifact-registry module (#2605)

In order to have a consistent interface across the different modules, this update will cause a delete/create of the existing permissions set in the iam variable:

  # module.artifact_registry.google_artifact_registry_repository_iam_binding.authoritative["roles/artifactregistry.reader"] will be created
  + resource "google_artifact_registry_repository_iam_binding" "authoritative" {
      + etag       = (known after apply)
      + id         = (known after apply)
      + location   = "europe"
      + members    = [
          + "allUsers",
        ]
      + project    = "xxredactedxx"
      + repository = "public"
      + role       = "roles/artifactregistry.reader"
    }

  # module.artifact_registry.google_artifact_registry_repository_iam_binding.bindings["roles/artifactregistry.reader"] will be destroyed
  # (because key ["roles/artifactregistry.reader"] is not in for_each map)
  - resource "google_artifact_registry_repository_iam_binding" "bindings" {
      - etag       = "xxredactedxx" -> null
      - id         = "xxredactedxx" -> null
      - location   = "europe" -> null
      - members    = [
          - "allUsers",
        ] -> null
      - project    = "xxredactedxx" -> null
      - repository = "projects/xxredactedxx/locations/europe/repositories/public" -> null
      - role       = "roles/artifactregistry.reader" -> null
    }

---

Checklist

I applicable, I acknowledge that I have:

• Read the contributing guide
• Ran terraform fmt on all modified files
• Regenerated the relevant README.md files using tools/tfdoc.py
• Made sure all relevant tests pass

[ludoo]

Thanks a lot for this. Can you also add relevant examples and inventories to the README? The contributing guide explains how those work, or ping here if you need a quick leg up.

[juliocc]

A few comments:

1. Move the IAM-related variables to variables-iam.tf
2. Move the IAM-related resources to iam.tf
3. Add the required dependencies to outputs
4. Make sure to implement the full interface explained here

[NitriKx]

Working on the tests sorry

[juliocc]

thanks for the quick response :)

Just one small detail with the moved block and we're good to go