BUG: CSS added via custom code persists after custom code component is removed

### GrapesJS version

- [X] I confirm to use the latest version of GrapesJS

### What browser are you using?

any

### Reproducible demo link

https://grapesjs.com/demo

### Describe the bug

**How to reproduce the bug?**
1. Add custom code component with HTML + CSS
2. Delete custom code component.

**What is the expected behavior?**
All code should be removed, including CSS

**What is the current behavior?**
custom CSS is **not** being removed, though the rest is.

[gjs.webm](https://github.com/user-attachments/assets/3fbd9a6d-ad0e-4fc6-add8-7cf31ae9293c)

### Code of Conduct

- [X] I agree to follow this project's Code of Conduct