Detect which feedstocks are using archived repositories as sources

[jaimergp]

and... hint? lint? Create issue?

The idea is that: if a feedstock is pulling from an archived repo, it should probably be archived too. Not sure how to best communicate this to the maintainers, though.

[jakirkham]

Looks like the GraphQL API's Repository query has an isArchived field

So we could check that to see if a repository is archived

[jakirkham]

Would add we already recommend users create an issue when archiving. So having a bot create that issue seems like a reasonable first stem