chore: Upload charm to latest/edge when main branch is updated

[saltiyazan]

Description

Currently we only release the charm to the release tracks (1.15 and 1.16).
In this change we add a workflow to release to latest/edge. This track will follow main which means it will have the same revision as in 1.16/edgefor now and later when there is a new release it will follow that release (for example1.17`)

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

[gruyaume]

Why release to latest at all? We should only release to release tracks (ex. 1.15, 1.16, 1.17).