Replace `golangpublicimages.azurecr.io` images

Our CI pipelines are currently puling some images from `golangpublicimages.azurecr.io/go-infra-images/prereqs`, which is deprecated and shouldn't be used. 

We should replace it with `mcr.microsoft.com/microsoft-go/infra-images`, whose images are generated from https://github.com/microsoft/go-infra-images.