test and review following PR in image updater to support multiple credentials per container registry:

https://github.com/argoproj-labs/argocd-image-updater/pull/547 

This PR aims to fix the community-requested feature:

Argo image updater config map configuration for multiple container registry from same registry #940
https://github.com/argoproj-labs/argocd-image-updater/issues/940

Multiple secrets for the same registry [ghcr.io] #639
https://github.com/argoproj-labs/argocd-image-updater/issues/639
https://github.com/argoproj-labs/argocd-image-updater/pull/642