gh-90325: Allow assert statements with parentheses

[pablogsal]

⚠️ PR created just to evaluate the solution, a PEP is needed before merging ⚠️

https://bugs.python.org/issue46167

• Issue: PEP 679: Parse assert (x == y, "Descriptive text") as statement params instead of a tuple #90325

[github-actions]

This PR is stale because it has been open for 30 days with no activity.

[StanFromIreland]

Just leaving a note here, the new syntax as implemented by the grammar change is not always consistent with the standard from. For example:

>>> t = ()
>>> assert *t # Standard form, raises SyntaxError
  File "<python-input-7>", line 1
    assert *t
           ^
SyntaxError: invalid syntax
>>> assert (*t, "error message") # New syntax is not used, passes due to the second element
<python-input-9>:1: SyntaxWarning: assertion is always true, perhaps remove parentheses?

Also, the current warning is not always correct:

>>> assert (*t,)
<python-input-6>:1: SyntaxWarning: assertion is always true, perhaps remove parentheses?
Traceback (most recent call last):
  File "<python-input-6>", line 1, in <module>
    assert (*t,)
           ^^^^^
AssertionError
>>>