Steps to reproduce
Create a code block, and set the highlighting language to something with special characters:
```😎cool😋language❤with💎special🔠characters👽
// code
```
Expected result
I expected to see the code block in the preview to get the corresponding class name language-😎cool😋language❤with💎special🔠characters👽
Actual result
Instead, inconsistent class names are seen. The <pre> gets class=" language-none", while the <code> gets both the expected class but also language-none, as shown:

Environment
- Operating system: Windows 10
- Obsidian version: v0.12.19