WIP: OCI Support for modules

[eunanio]

Summary

This PR adds a native OCI support to tofu. Allowing the user to use any oci registry as a source for tofu modules. This change includes support for registry authentication via docker login and the ability to publish existing modules.

Usage

As a module source

module "s3-oci" {
  source = "oci://registry.gitlab.com/mysql-rds:v1.0.0"
  bucket_name = "test.company.bucket.com"
}

Publish a new oci module

# tofu oci push <tag> <path>
tofu oci push registry.gitlab.com/mysql-rds:v1.0.0 ./modules/mysql-rds

Pull a module from registry

# tofu oci pull <tag>
tofu oci pull registry.gitlab.com/mysql-rds:v1.0.0

Authentication

This implementation uses your docker credentials for authenticating oci requests. This should make it easier to integrate with CI/CD like github actions.

Resolves #31463

Target Release

1.10.0

Checklist

• I have read the contribution guide.
• I have not used an AI coding assistant to create this PR.
• I have written all code in this PR myself OR I have marked all code I have not written myself (including modified code, e.g. copied from other places and then modified) with a comment indicating where it came from.
• I (and other contributors to this PR) have not looked at the Terraform source code while implementing this PR.

Go checklist

• I have run golangci-lint on my change and receive no errors relevant to my code.
• I have run existing tests to ensure my code doesn't break anything.
• I have added tests for all relevant use cases of my code, and those tests are passing.
• I have only exported functions, variables and structs that should be used from other packages.
• I have added meaningful comments to all exported functions, variables, and structs.

Website/documentation checklist

• I have locally started the website as described here and checked my changes.

[github-actions]

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