Depend on go-test before launching cross-build job

The cross build job is a fan-out style job which puts a fixed cost on the build system and uploads potentialy dozens of megabytes per combination.

To avoid wasting cycles on broken tests, build all the variants only after the unit tests have passed.

Signed-off-by: Zygmunt Krynicki zygmunt.krynicki@huawei.com