Say loudly, not fail, where a check has no bubblewrap to run a build module's shut-off steps (issue 1309)

build-agent's check container has no bwrap; the build nodes, where the checker runs from
R4e, do. The sibling test and the real Node build skip naming it, and the pull-head pin
test still runs its fetch half and skips only the shut-off build.

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

@@ -17,7 +17,7 @@ import (
 // registry for @novox, which reads without a credential) and makes two workspaces holding one fixture bundle.
 func realMachine(t *testing.T) (*Module, string) {
 	t.Helper()
-	for _, p := range []string{"node", "npm"} {
+	for _, p := range []string{"node", "npm", "bwrap"} { // bwrap: tsc, esbuild and the scripts run shut off (1309)
 		if _, err := exec.LookPath(p); err != nil {
 			t.Skipf("NOT RUN: no %s installed where this check runs (the mesh's Go toolchain image holds none); proven live on a build node", p)
 		}