BuildStream doesn't check that the artifact remotes has the required capabilities
Summary
As seen in https://gitlab.com/BuildStream/buildstream/-/jobs/327518918, when trying to connecting to remote artifact caches that are for bst1, BuildStream doesn't check the capabilities and skip them anymore
What is the current bug behavior?
BuildStream fails when a remote artifact cache is missing some capabilities
What is the expected correct behavior?
BuildStream should check for capabilities whenever trying a remote artifact cache