stats: remove deprecated arguments -stats{enabled,hostname,ns}

[kwvg]

Breaking Changes

• The arguments -statsenabled, -statsns, -statshostname have been removed. They were previously deprecated in v22.0 and will no longer be recognized on runtime.

Checklist

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have made corresponding changes to the documentation
• I have assigned this pull request to a milestone (for repository code-owners and collaborators only)