m/node/core/time: use CommandContext

Change-Id: Ie98b949facf3d26c819bdf56329f5837b8e3dac7
Reviewed-on: https://review.monogon.dev/c/monogon/+/3712
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/metropolis/node/core/time/time.go b/metropolis/node/core/time/time.go
index 3e37a0c..bd66e65 100644
--- a/metropolis/node/core/time/time.go
+++ b/metropolis/node/core/time/time.go
@@ -47,7 +47,7 @@
 		return fmt.Errorf("cannot create fileargs: %w", err)
 	}
 	defer args.Close()
-	cmd := exec.Command(
+	cmd := exec.CommandContext(ctx,
 		"/time/chrony",
 		"-d",
 		"-i", strconv.Itoa(node.TimeUid),