`pants check::` doesnt use reliable versions

when you run `pants check some.package::` it uses the dependencies that are specified in the package BUILD files

when you run `pants check::` it ignores these and just uses the local versions if they are also being tested

i have raised this upstream, not least because you would expect the results to be the same running against each package, and running against all packages

i also tried to resolve this by running against each package separately, but the performance is terrible - i believe this is something being looked at upstream