Health bot - Package publish validation should list packages as `publish_to: none`

[dcharkes]

Currently the health bot package publish validation omits packages that have publish_to: none in their pubspec.

Maybe we should consider listing them? (E.g. we were confused by why the packages where not showing up.)

Possible downside: any example packages inside a package will start showing up as well. Can we somehow identify packages which are temporarily set to publish_to: none and ones which are meant to always stay publish_to: none? For example in mono repos all packages in pkgs/xxx should be published but packages in pkgs/xxx/example not. But that feels fragile.

cc @mosuem

[mosuem]

We have the ignore_packages glob, which could be set to ignore anything beneath an example/ folder by default, and then remove the special-casing of publish_to: none.