Add support for Python 3.14 multi-exception syntax

[erictraut]

Python 3.14 relaxes the syntax for except clauses that accept multiple exception types but do not use an as clause. Previously, parentheses were required in this case, but 3.14 eliminates this requirement.

def divide(a, b):
    try:
        result = a / b
        return result
    except ZeroDivisionError, TypeError: # No Parens needed here (unless there's an as clause)
        print(f"Wrong input: {a} and {b}")
        raise

See PEP 758 for details.

[erictraut]

This is addressed in pyright 1.1.402.