The workflows defined respectively in build.yaml and snap.yaml were
both called "CI". On the Github web interface, it resulted in two menus
called "CI" with no easy way to know which is which.
To make things clearer, we now:
* rename build.yaml -> ci.yaml
* call "Snap" the workflow defined by snap.yaml
Signed-off-by: Olivier Gayot <olivier.gayot@canonical.com>
(cherry picked from commit a34bce470f)