Skip pgp-happy-eyeballs on build tests

[yosifkit]

This is the workaround for stale servers that we are seeing in #11917 (comment) and #11727 (comment).

Using this line in generate.sh to skip pgp-happy-eyeballs setup.

I don't think we should remove pgp-happy-eyeballs from the build servers since we haven't hit the stale keyservers there. This can be re-enabled once tianon/pgp-happy-eyeballs#4 has a proper solution.

[tianon]

This can be re-enabled once tianon/pgp-happy-eyeballs#4 has a proper solution.

IMO, we shouldn't re-enable this -- pgp-happy-eyeballs was designed for a time when SKS was relatively healthy, which really isn't the case anymore. The "gossip network" might still be alive and active, but finding a good, up-to-date list of "which servers should we consider as OK" is a very challenging problem that I don't think is worth solving.

Both hkps://keys.openpgp.org and hkps://keyserver.ubuntu.com are great, stable replacements that work well and solve the problem to the extent any of our image builds actually require. 🙈

I think we should probably adjust the wording in https://github.com/docker-library/faq#openpgp--gnupg-keys-and-verification to make the current situation (and our suggested "solutions", ie those two keyservers, preferred in that order) more clear.