[fuzz] Pre-existing Python front-end bug (seed 1777894483)

A fuzz test found a pre-existing failure in the Python front-end.

**Seed:** `1777894483`
**PR:** #984
**Merge base also fails:** yes

### Reproduce
```bash
cd Tools/Python
./scripts/hypothesmith.sh 10 1777894483 both --unrestricted
```

This bug exists on `main` and was not introduced by the PR.