aider: Changed the way subprocess.run is mocked in test_check_for_ctags_success to return different results for each call.

# Context:
USER: in `test_check_for_ctags_success` we need to mock `subprocess`.run differently. it will be called twice and needs to return different results for each call.
ASSISTANT: To modify the `test_check_for_ctags_success` method in the `tests/test_repomap.py` file, we need to change the way `subprocess.run` is mocked. It will be called twice and needs to return different results for each call.

Here are the steps to make the changes:

1. Import `MagicMock` from `unittest.mock`.
2. Replace the `mock_run.return_value` with `mock_run.side_effect` which is a list of `CompletedProcess` objects. The first one simulates a successful call to `ctags --version` and the second one simulates a successful call to `ctags -R`.

Here is the *edit block* for the changes:

```python
tests/test_repomap.py
<<<<<<< ORIGINAL
from unittest.mock import patch
from subprocess import CompletedProcess

def test_check_for_ctags_success(self):
    with patch("subprocess.run") as mock_run:
        mock_run.return_value = CompletedProcess(
            args=["ctags", "--version"],
            returncode=0,
            stdout=(
                b'{"_type": "tag", "name": "status", "path": "aider/main.py", "pattern": "/^   '
                b' status = main()$/", "kind": "variable"}'
            ),
        )
        repo_map = RepoMap()
        result = repo_map.check_for_ctags()
        self.assertTrue(result)
=======
from unittest.mock import patch, MagicMock
from subprocess import CompletedProcess

def test_check_for_ctags_success(self):
    with patch("subprocess.run") as mock_run:
        mock_run.side_effect = [
            CompletedProcess(
                args=["ctags", "--version"],
                returncode=0,
                stdout=b"Universal Ctags 0.0.0(f25b4bb7)",
            ),
            CompletedProcess(
                args=["ctags", "-R"],
                returncode=0,
                stdout=b"",
            ),
        ]
        repo_map = RepoMap()
        result = repo_map.check_for_ctags()
        self.assertTrue(result)
>>>>>>> UPDATED
```

This change will make the `test_check_for_ctags_success` method simulate two calls to `subprocess.run` with different results.

tests/test_repomap.py

@@ -88,20 +88,26 @@ print(my_function(3, 4))
             result = repo_map.check_for_ctags()
             self.assertFalse(result)
 
+from unittest.mock import patch, MagicMock
+from subprocess import CompletedProcess
+
 def test_check_for_ctags_success(self):
     with patch("subprocess.run") as mock_run:
-            mock_run.return_value = CompletedProcess(
+        mock_run.side_effect = [
+            CompletedProcess(
                 args=["ctags", "--version"],
                 returncode=0,
-                stdout=(
+                stdout=b"Universal Ctags 0.0.0(f25b4bb7)",
-                    b'{"_type": "tag", "name": "status", "path": "aider/main.py", "pattern": "/^   '
-                    b' status = main()$/", "kind": "variable"}'
             ),
-            )
+            CompletedProcess(
+                args=["ctags", "-R"],
+                returncode=0,
+                stdout=b"",
+            ),
+        ]
         repo_map = RepoMap()
         result = repo_map.check_for_ctags()
         self.assertTrue(result)
-
     def test_get_repo_map_without_ctags(self):
         # Create a temporary directory with a sample Python file containing identifiers
         test_files = [