Reject parenthesized star imports (#26021)
## Summary
Reject parenthesized star imports such as:
```python
from module import (*)
```
Python only permits a bare star in `from` imports. The parser previously
accepted the parenthesized form because star aliases were parsed
independently of the surrounding import-list delimiters.
This adds the missing parser validation while preserving ordinary
parenthesized imports and bare star imports.
