aider: Fixed prompt() function call in get_input() method to pass stdin and stdout arguments instead of input and output.

# Context:
USER: FAILED tests/test_main.py::TestMain::test_main_with_empty_git_dir_new_file - TypeError: prompt() got an unexpected keyword argument 'input'
ASSISTANT: I apologize for the confusion. It seems I made a mistake in the `prompt_toolkit.prompt()` function call. The `prompt()` function accepts `stdin` and `stdout` arguments instead of `input` and `output`. Here's the fix:

Update the `prompt()` function call in the `get_input()` method in `aider/getinput.py`:

```python
aider/getinput.py
<<<<<<< ORIGINAL
            input=self.input,
            output=self.output,
=======
            stdin=self.input,
            stdout=self.output,
>>>>>>> UPDATED
```

These changes will ensure that the `input` and `output` arguments are passed correctly to the `prompt_toolkit.prompt()` function.

aider/getinput.py

@@ -125,8 +125,8 @@ class InputOutput:
                 style=style,
                 reserve_space_for_menu=4,
                 complete_style=CompleteStyle.MULTI_COLUMN,
-                input=self.input,
-                output=self.output,
+            stdin=self.input,
+            stdout=self.output,
             )
             if line.strip() == "{" and not multiline_input:
                 multiline_input = True