Remove field `manifests.helm.releases[].createNamespace` and instead suggest users to use `deploy.helm.releases[].createNamespace`

[aaron-prindle]

After Skaffold v2, the original helm deploy schema configuration was duplicated into manifests.helm and deploy.helm locations. Some fields do not make sense in both location though, specifically manifests.helm.releases[].createNamespace does not make sense to have in render config has no resources are expected to be created there (just manifest creation) (this is currently not working as well, see - #8515). deploy.helm.releases[].createNamespace currently works as intended though and is the correct place for this

[ericzzzzzzz]

manifests.helm and deploy.helm use the same struct, the work here may not be trivial