Rendering the external YAML data of a host causes Foreman to generate incorrect data if it includes hashes that are set in parameterised classes.

Generated YAML:

classes:
  easystack:
    ceph_monitors:
    - !ruby/hash:ActiveSupport::HashWithIndifferentAccess
      fqdn: [RETRACTED]
      ip:  [RETRACTED]
      master: true
    - !ruby/hash:ActiveSupport::HashWithIndifferentAccess
      fqdn:  [RETRACTED]
      ip:  [RETRACTED]
      master: true
    - !ruby/hash:ActiveSupport::HashWithIndifferentAccess
      fqdn:  [RETRACTED]
      ip:  [RETRACTED]
      master: true

This seems to be a duplicate of #9240 and was introduced again somewhere between 1.16.1 and 1.17.0.