[3.5 regression] `[error] Cannot read properties of undefined (reading 'length')`

**Environments:**

- Prettier Version: 3.5.0
- Running Prettier via: CLI
- Runtime: Node.js 22
- Operating System: Ubuntu
- Prettier plugins (if any): N/A

**Steps to reproduce:**

```
npm exec -- prettier --cache --write src/background.ts
```

**Expected behavior:**

Formats the code.

**Actual behavior:**

`[error] Cannot read properties of undefined (reading 'length')`
