cmd: prefer nil slices over zero-length slices (#19077)

cmd/utils/flags.go

@@ -1613,7 +1613,7 @@ func MakeConsolePreloads(ctx *cli.Context) []string {
 		return nil
 	}
 	// Otherwise resolve absolute paths and return them
-	preloads := []string{}
+	var preloads []string
 
 	assets := ctx.GlobalString(JSpathFlag.Name)
 	for _, file := range strings.Split(ctx.GlobalString(PreloadJSFlag.Name), ",") {