Skip snapshots that can't be processed, rather than failing the whole update

[chreekat]

A nice improvement to the situation we presently find ourselves in (#358, #359)

[juhp]

I still wonder whether reverting the snapshots from stackage-snapshots, if that it is the source of the problem, wouldn't be the simplest short term quick solution. I dunno if nixpkgs uses it or what else?

[chreekat]

I think skipping failed snapshots would be a good improvement in any case.