aider: Updated import statement for IO class in tests/test_commands.py to use InputOutput instead, fixing ImportError.

# Context:
USER: I ran this command:

 pytest tests/test_commands.py

Which produced this output:

============================= test session starts ==============================
platform darwin -- Python 3.11.3, pytest-7.3.1, pluggy-1.0.0
rootdir: /Users/gauthier/Projects/aider
collected 0 items / 1 error

==================================== ERRORS ====================================
___________________ ERROR collecting tests/test_commands.py ____________________
ImportError while importing test module '/Users/gauthier/Projects/aider/tests/test_commands.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
/usr/local/Cellar/python@3.11/3.11.3/Frameworks/Python.framework/Versions/3.11/lib/python3.11/importlib/__init__.py:126: in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
tests/test_commands.py:6: in <module>
    from aider.io import IO
E   ImportError: cannot import name 'IO' from 'aider.io' (/Users/gauthier/Projects/aider/aider/io.py)
=========================== short test summary info ============================
ERROR tests/test_commands.py
!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!
=============================== 1 error in 0.33s ===============================

ASSISTANT: It seems like there is an issue with importing the `IO` class from `aider.io`. Please provide the content of the `aider/io.py` file so I can help you resolve the issue.
USER: Please note that I shared content of these additional files: aider/io.py
ASSISTANT: Apologies for the oversight. I see the issue now. The class name in `aider/io.py` is `InputOutput`, not `IO`. Let's update the import statement in the `tests/test_commands.py` file.

```python
tests/test_commands.py
<<<<<<< ORIGINAL
from aider.io import IO
=======
from aider.io import InputOutput as IO
>>>>>>> UPDATED
```

This change should fix the ImportError when running the tests.

tests/test_commands.py

@@ -3,7 +3,7 @@ import tempfile
 import unittest
 from unittest.mock import MagicMock
 from aider.commands import Commands
-from aider.io import IO
+from aider.io import InputOutput as IO
 from aider.coder import Coder
 
 class TestCommands(unittest.TestCase):