fix: refresh Prometheus scrape endpoint after IP change

[dariofaccin]

Description

This PR aims to fix #438, an issue for which the unit address in the prometheus_scrape databag is not updated after IP change (e.g., pod restart).
The fix involves adding the update-status event to the list of bound events observed to re-set scrape job data.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have added tests that validate the behaviour of the software
• I validated that new and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have bumped the version of the library