Add support for auditor_groups with OIDC provider

What does this MR do and why?

This MR complete the work done in !111904 (merged) by adding support for syncing auditor status with the OIDC provider.

It fixes #389321 (closed)

How to set up and validate locally

Follow the same instruction as for the administrator groups section in the documentation by substituting administrator_groups with auditor_groups.

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.