Hold every build module to ending what a previous process left running (issue 1890)

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.

modules/mesh-build-node/cmd/mesh-build-node/main.go

@@ -9,7 +9,6 @@ package main
 import (
 	"context"
 	"fmt"
-	"git.novox.be/novox/mesh-sdk/go/buildstep"
 	"os"
 	"os/user"
 	"path/filepath"
@@ -75,8 +74,9 @@ func main() {
 	puller := m.Puller(steps, nil)
 	m.Held = puller
 	if m.Node != "" {
-		// A step a previous process left running is ended (issue 1890); this process's own steps start after booted.
-		go buildstep.EndStaleAtStart(ctx, m.stepScan(), m.Node, booted, logf)
+		// A step a previous process left running is ended (issue 1890): one that names another owner, or none and
+		// started before booted.
+		go m.endLeftRunning(ctx, m.stepScan(), booted, logf)
 	}
 	if m.Node != "" {
 		// The seat's asks, pulled once Serve has the runtime's channel; a pull before it is said and tried again.