Downstream testing CI changes

[Samuel-amap]

• Dev branch removal
• Fail action unless the tests check against dependencies main/master (enables testing with a downstream package PR, and ensures dependencies are in a 'releasable' state before tests pass).

[Samuel-amap]

Behaviour works as intended.

A couple of points that might need some consideration :

• We might want to point at the latest release, occasionally, instead of testing against the main/master branches of dependencies.
• If a version incompatibility is detected, the integration check is successful. It is understandable behaviour, but is this always desirable ? I think this doesn't cause a problem because it'll be caught when working on and testing the downstream dependency directly in this kind of scenario. There might be other side-effects I'm not taking into consideration that cause workflow issues, though.