Fix architectures for many suites

This follows my having a look at the config for !1 (closed), but is independent from it.

I think fixing experimental would make sense (with an upcoming merge request for dak), fixing for bullseye might (depending on release team/ftp team feedback regarding point releases); the other two, probably not. I'm not sure whether it's best to remove them from the configuration file entirely at this point. They were missing several archs, but then dep11/ wasn't as important as it is now.