[`flake8-blind-except`] Change `BLE001` to correctly parse exception tuples (#19747)
## Summary
This PR enhances the `BLE001` rule to correctly detect blind exception
handling in tuple exceptions. Previously, the rule only checked single
exception types, but Python allows catching multiple exceptions using
tuples like `except (Exception, ValueError):`.
## Test Plan
It fails the following (whereas the main branch does not):
```bash
cargo run -p ruff -- check somefile.py --no-cache --select=BLE001
```
```python
# somefile.py
try:
1/0
except (ValueError, Exception) as e:
print(e)
```
```
somefile.py:3:21: BLE001 Do not catch blind exception: `Exception`
|
1 | try:
2 | 1/0
3 | except (ValueError, Exception) as e:
| ^^^^^^^^^ BLE001
4 | print(e)
|
Found 1 error.
```