Token matching generates an exception when index is None

[barsa-net]

Describe the bug
Using token_matching with index None generates an TypeError exception

To Reproduce
Executing the following code

import sqlparse

p = sqlparse.parse("SELECT id FROM table")[0]
p.token_matching([lambda x: isinstance(x, sqlparse.sql.Token)], None)

generates an exception

Traceback (most recent call last):
  File "/repositories/github/sqlparse/t.py", line 4, in <module>
    p.token_matching(lambda x: isinstance(x, sqlparse.sql.Token), None)
  File "/repositories/github/sqlparse/sqlparse/sql.py", line 277, in token_matching
    return self._token_matching(funcs, idx)[1]
TypeError: 'NoneType' object is not subscriptable

Expected behavior
token_matching should return None

Versions (please complete the following information):

• Python: 3.9.18
• sqlparse: git commit f101546