remove unused Domain.published_snapshots
remove unused Domain.published_snapshots

removed in 4e653af5ade177b557263f22edc00e3c1bea44c1

qedsoftware/commcare-hq,qedsoftware/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq,qedsoftware/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq,qedsoftware/commcare-hq,qedsoftware/commcare-hq