aider: Added write_text function to InputOutput class in aider/io.py.

# Context:
USER: add a write_text func
ASSISTANT: To add a `write_text` function to the `InputOutput` class in the `aider/io.py` file, we need to modify the `aider/io.py` file.

Here is the change:

```python
aider/io.py
<<<<<<< ORIGINAL

    def read_text(self, filename):
        try:
            with open(filename, "r", encoding=self.encoding) as f:
                return f.read()
        except (FileNotFoundError, UnicodeError) as e:
            self.tool_error(f"{filename}: {e}")
            return
=======

    def read_text(self, filename):
        try:
            with open(filename, "r", encoding=self.encoding) as f:
                return f.read()
        except (FileNotFoundError, UnicodeError) as e:
            self.tool_error(f"{filename}: {e}")
            return

    def write_text(self, filename, content):
        try:
            with open(filename, "w", encoding=self.encoding) as f:
                f.write(content)
        except (FileNotFoundError, UnicodeError) as e:
            self.tool_error(f"{filename}: {e}")
            return
>>>>>>> UPDATED
```

This `write_text` function takes a filename and content as arguments, opens the file in write mode, and writes the content to the file. If there is a `FileNotFoundError` or `UnicodeError`, it calls the `tool_error` method with the error message.

aider/io.py

@@ -134,7 +134,7 @@ class InputOutput:
 
         current_time = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
         self.append_chat_history(f"\n# aider chat started at {current_time}\n\n")
-
+    
     def read_text(self, filename):
         try:
             with open(filename, "r", encoding=self.encoding) as f:
@@ -143,6 +143,14 @@ class InputOutput:
             self.tool_error(f"{filename}: {e}")
             return
 
+    def write_text(self, filename, content):
+        try:
+            with open(filename, "w", encoding=self.encoding) as f:
+                f.write(content)
+        except (FileNotFoundError, UnicodeError) as e:
+            self.tool_error(f"{filename}: {e}")
+            return
+
     def get_input(self, root, rel_fnames, addable_rel_fnames, commands):
         if self.pretty:
             style = dict(style=self.user_input_color) if self.user_input_color else dict()