Property 'Unit' does not exist on type 'MathJsStatic'. Did you mean 'unit'? error in Typescript

When creating the following code in Typescript

```
import { MathJsStatic, create, all, MathType } from 'mathjs';
const math: MathJsStatic = create(all, {}) as MathJsStatic;

math.createUnit('cells'); // works perfectly
math.Unit; // results in: Property 'Unit' does not exist on type 'MathJsStatic'. Did you mean 'unit'?
```

It looks like Unit isn't properly part of the new MathJS typescript definitions or it's not linking correctly.

if I replace the line above with `window['testing'] = math` then the Unit is in fact present.


Edit: I am running mathjs 9.4.4 without `@types/mathjs` (relying on the built-in type definitions)