Removing excluded users from ListUsers response

[willvedd]

Description

Removes excluded_users from ListUsers response as it was removed from OpenFGA with openfga/api#171 and openfga/sdk-generator#377.

This feature was originally a well-intentioned way to communicate any negations that may exist on public-typed wildcard (e.g. user:) as a means of being abundantly clear about what a user: result entails. However, as we discover more possible situations where excluded users could arise, we realize that we were making a premature decision about the API. We fully intend to re-add excluded_users at some point in the future but may or may not be a flattened list as previously implemented.

This was tested with a locally-generated version of the Go SDK.

Please note:

• This is a draft until the Go SDK is rebuilt
• This is technically a breaking but is acceptable provided that the ListUsers API is still experimental

References

• Related SDK Generator change: Removing excluded users from ListUsers response sdk-generator#377
• Related OpenFGA API change: Removing excluded users api#171

Review Checklist

• I have clicked on "allow edits by maintainers".
• I have added documentation for new/changed functionality in this PR or in a PR to openfga.dev [Provide a link to any relevant PRs in the references section above]
• The correct base branch is being used, if not main
• I have added tests to validate that the change in functionality is working as expected