Give the late build-seat holder a broker account so its worker is derived (issue 1931)

cmd/mesh-controller/busobjects_test.go

@@ -51,11 +51,9 @@ func aCarriedConsumer(t *testing.T, open *stores) broker.Consumer {
 // seat's first accepted kind (the build agent's seat, which had one worker for all, is gone with the builder).
 func aLateHolder(t *testing.T, open *stores) broker.Consumer {
 	t.Helper()
-	// The seat's rows are what a claim of it is composed against (a pulled-by-kind seat's workers come from them).
-	if _, err := open.inventory.SeedSeats(t.Context(), catalogue.DefaultSeats()); err != nil {
-		t.Fatal(err)
-	}
+	// With an account to read, as a holder has: a module with none is no bus user, so its seat's workers are not derived.
 	register(t, open, catalogue.Manifest{Module: "late-builder", Version: "1",
+		OwnSecrets: catalogue.OwnSecrets{"broker": {Path: "/var/lib/mesh/late-builder/broker"}},
 		Claims: []catalogue.Claim{{Name: "node-build-go", Scope: catalogue.ScopeNode}}})
 	if _, err := open.inventory.Assign(t.Context(), "anchor", "late-builder"); err != nil {
 		t.Fatal(err)