doc: fix vm.runInNewContext signature

The `options` parameter cannot be passed without `sandbox`.

PR-URL: #21824
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

doc/api/vm.md

@@ -758,7 +758,7 @@ console.log(util.inspect(sandbox));
 // { globalVar: 1024 }
 ```
 
-## vm.runInNewContext(code[, sandbox][, options])
+## vm.runInNewContext(code[, sandbox[, options]])
 <!-- YAML
 added: v0.3.1
 -->