Weird cyrillic symbols transformation in schema generation

Assuming we have such a type

```haskell
type SomeCode = SchemaText '[TRegex "^[0-9A-ZА-Я]{2}$"]
```

but the result scheme looks like

```json
    "items": {
        "pattern": "^[0-9A-ZÐ-Ð¯]{2}$",
        "type": "string"
    }
```

Looks like some strange hangling of non-ascii symbols somewhere.