Remove/Delete old image after successful update

[dibu28]

Is your feature request related to a problem? Please describe.

Remove/Delete old Docker image after successful container update to clean up disk space used by old images.

At some point I had a problem of no disk space left on Docker server because all space was used by old images left after Watchtower updates.

Describe the solution you'd like

Add setting config to remove old image on successful update or at least remove last number of image versions l.

Describe alternatives you've considered

Or create separate helper container for Watchtower to perform cleanup. Cleantower)

Additional context

No response

[github-actions]

Hi there! 👋🏼 As you're new to this repo, we'd like to suggest that you read our code of conduct as well as our contribution guidelines. Thanks a bunch for opening your first issue! 🙏