chore: Release stackable-operator 0.79.0

[sbernauer]

Added

• Re-export the YamlSchema trait and the stackable-shared crate as the shared module (#883).
• BREAKING: Added preferredAddressType field to ListenerClass CRD (#885).
• BREAKING: The cluster domain (default: cluster.local) can now be configured in the individual
  operators via the ENV variable KUBERNETES_CLUSTER_DOMAIN or resolved automatically by parsing
  the /etc/resolve.conf file. This requires using initialize_operator instead of create_client
  in the main.rs of the individual operators (#893).

Changed

• BREAKING: The CustomResourceExt trait is now re-exported from the stackable-shared crate. The
  trait functions use the same parameters but return a different error type (#883).
• BREAKING: KeyValuePairs (as well as Labels/Annotations via it) is now backed by a BTreeMap
  rather than a BTreeSet (#888).
  • The Deref impl now returns a BTreeMap instead.
  • iter() now clones the values.

Fixed

• BREAKING: KeyValuePairs::insert (as well as Labels::/Annotations:: via it) now overwrites
  the old value if the key already exists. Previously, iter() would return both values in
  lexicographical order (causing further conversions like Into<BTreeMap> to prefer the maximum
  value) (#888).

Removed

• BREAKING: The CustomResourceExt trait doesn't provide a generate_yaml_schema function any
  more. Instead, use the high-level functions to write the schema to a file, write it to stdout or
  use it as a String (#883).