A replaced mesh-build-go left a check ask's step running and its start
sweep spared it (issue 1890, note 21). mesh-build-go, mesh-build-node and
mesh-build-image pin mesh-sdk 981a35b5, whose steps name their owner and
whose sweep ends another owner's at once; each runs the sweep through one
method that main calls and that its test runs through the conformance
kit's left-running case. The failurekit check now refuses a build module
whose tests do not run that case, test step or not.