Weather server missing main function

The weather server script does not run.

```
❯ uv run weather
Traceback (most recent call last):
  File "/projects/quickstart-resources/weather-server-python/.venv/bin/weather", line 4, in <module>
    from weather import main
ImportError: cannot import name 'main' from 'weather' (/projects/quickstart-resources/weather-server-python/weather.py)
```

The script definition in `pyproject.toml` is looking for a `main` function which does not exist.

weather-server-python/weather.py

@@ -89,6 +89,9 @@ Forecast: {period['detailedForecast']}
 
     return "\n---\n".join(forecasts)
 
-if __name__ == "__main__":
+def main():
     # Initialize and run the server
-    mcp.run(transport='stdio')
+    mcp.run(transport='stdio')    
+
+if __name__ == "__main__":
+    main()