[Refactor] Clean up the `version-bump:charts:`

The charts does not use deps.io anymore. With that version-bump:{charts|cng|omnibus}: and all the main.go {charts|cng|omnibus} logic could be removed.

The update now happens with renovate which gets triggered every 15-30 minutes. The dependency bot pipeline simply is not there anymore, so it won't do anything triggering a pipeline with that special variable.