vendor in latest buildah

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

vendor/github.com/containers/buildah/chroot/run_common.go

@@ -501,6 +501,10 @@ func runUsingChroot(spec *specs.Spec, bundlePath string, ctty *os.File, stdin io
 	// Apologize for the namespace configuration that we're about to ignore.
 	logNamespaceDiagnostics(spec)
 
+	// We need to lock the thread so that PR_SET_PDEATHSIG won't trigger if the current thread exits.
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
 	// Start the parent subprocess.
 	cmd := unshare.Command(append([]string{runUsingChrootExecCommand}, spec.Process.Args...)...)
 	setPdeathsig(cmd.Cmd)