Option to not render first tempo expression (e.g. "Allegro", "Andante")

```js
osmd.EngravingRules.RenderFirstTempoExpression = false;
```

Before:
<img width="1599" height="439" alt="Image" src="https://github.com/user-attachments/assets/c6e3a97a-7eb5-4831-95a2-5890435d3406" />

After:
<img width="1606" height="431" alt="Image" src="https://github.com/user-attachments/assets/d455c16c-fd4d-441f-837f-c09e73b6228c" />

(also called tempo marking, tempo indication)