Add main guard to icon example script

Wrapped the ft.run(main) call in a __name__ == "__main__" guard to prevent unintended execution when the module is imported.

Author: FeodorFitsner

sdk/python/examples/controls/icon/basic.py

@@ -37,4 +37,5 @@ def main(page: ft.Page):
     )
 
 
-ft.run(main)
+if __name__ == "__main__":
+    ft.run(main)