This ensures that warning blocks about overriding the Helm version of a
chart via target customizations are properly indented and formatted,
even when embedded in lists.
This adds a warning for Fleet versions from 0.6 onwards about bundle
sizes which may exceed etcd's maximum blob size for bundles containing
multiple versions of a chart as a result of target customisations.
Fleet versions prior to 0.6 did not properly support multiple chart
versions per bundle, hence that warning is not relevant for them.
Corentin Néau