Initialize project with kubebuilder init.

[joshlreese]

This PR introduces the boilerplate produced by kubebuilder init. No APIs or controllers have been defined yet, and the generated content has not been tweaked much. Golang has been bumped from 1.22 to 1.23.

Command executed:

kubebuilder init --domain datumapis.com \
  --repo go.datum.net/workload-operator \
  --license none \
  --owner 'Datum Technology, Inc.' \
  --project-name workload-operator

This PR is similar in spirit to datum-cloud/network-services-operator#1, and will be followed by additional PRs for APIs and controllers.