Accept user param for cirun cli to adding access to resource

[aktech]

As discussed here conda-forge/.cirun#25 (comment) with @jaimergp

At the moment conda-smithy doesn't passes users in the call to cirun.add_repo_to_resources:

conda-smithy/conda_smithy/cirun_utils.py

Line 68 in b2075e6

response = cirun.add_repo_to_resources(

To add a specific set of users access to a resource (cirun github actions runner) for a repository.
See https://py.cirun.io/api.html#parameters

It would be great to add this param in the cli like --cirun-users, so that it can be used in the admin-requests here: https://github.com/conda-forge/admin-requests/blob/9829bac218b6726d2a7b29a9d9f8d7d22f3084d7/conda_forge_admin_requests/access_control.py#L155

Such that pull requests like these: conda-forge/.cirun#25 can be automatically created by @cirun-bot when admin requests calls conda-smithy with this param, which in turn passes it to cirun client.

Relevant issue in admin-requests: conda-forge/admin-requests#1237