The AddVisibilityLevelToGroups migration introduced a visibility_level for
namespaces and specified that projects should always have a visibility level
less than or equal to their namespace. However, some invalid rows could have
been created.
This commit introduces a migration that updates the invalid rows, setting the
invalid project to have the same visibility_level as their namespaces. This
will make some projects internal or private when they would previously have
been public or internal, but this is better than silently making an internal
or private group public.
These are regular Rails migrations that are executed by default. A user
can opt-out of these migrations by setting an environment variable
during the deployment process.
Fixesgitlab-org/gitlab-ce#22133