chore: use new repo for snap publish action

[gruyaume]

Description

Use new repo for snap publish action.

Rationale

Our CI is failing at the snap-publish step because the repo was moved from snapcore to canonical and the git tags were removed from the old one.

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