aider: Added subprocess module to run git init in the temporary directory before calling main in test_main_with_empty_git_dir_new_file.

# Context:
USER: in test_main_with_empty_git_dir_new_file, run git init in the new dir before calling main
ASSISTANT: To run `git init` in the new directory before calling `main`, you can use the `subprocess` module to execute the command. Here's the change you need to make in the `test_main_with_empty_git_dir_new_file` function:

```python
tests/test_main.py
<<<<<<< ORIGINAL
    def test_main_with_empty_git_dir_new_file(self):
        with tempfile.TemporaryDirectory() as temp_dir:
            os.chdir(temp_dir)
            with open(os.devnull, 'r') as dev_null:
                save_stdin = sys.stdin
                sys.stdin = dev_null
                main(['foo.txt'])
                sys.stdin = save_stdin
=======
    import subprocess

    def test_main_with_empty_git_dir_new_file(self):
        with tempfile.TemporaryDirectory() as temp_dir:
            os.chdir(temp_dir)
            subprocess.run(["git", "init"])
            with open(os.devnull, 'r') as dev_null:
                save_stdin = sys.stdin
                sys.stdin = dev_null
                main(['foo.txt'])
                sys.stdin = save_stdin
>>>>>>> UPDATED
```

This change imports the `subprocess` module and adds the `subprocess.run(["git", "init"])` line to run `git init` in the temporary directory before calling `main`.

tests/test_main.py

@@ -23,3 +23,15 @@ class TestMain(TestCase):
                 main(['foo.txt'])
                 sys.stdin = save_stdin
                 self.assertTrue(os.path.exists('foo.txt'))
+
+    import subprocess
+
+    def test_main_with_empty_git_dir_new_file(self):
+        with tempfile.TemporaryDirectory() as temp_dir:
+            os.chdir(temp_dir)
+            subprocess.run(["git", "init"])
+            with open(os.devnull, 'r') as dev_null:
+                save_stdin = sys.stdin
+                sys.stdin = dev_null
+                main(['foo.txt'])
+                sys.stdin = save_stdin