F821 false positive in else when except block locals matches try block locals.

Sometime between 0.0.265 and 0.0.274, ruff started failing on this case:

```
try:
    v = 3
except ImportError as v:
    print(v)
else:
    print(v)
```

with 

```
e.py:6:11: F821 Undefined name `v`
```

This issue was encountered in pypa/setuptools#3961.