make the open() call in the "Change Target File" option explicitly specify utf-8 encoding

Author: shaggysa

pybricksdev/cli/__init__.py

@@ -316,7 +316,8 @@ async def reconnect_hub():
                                                 "What file would you like to use?"
                                             ).ask_async()
                                         )
-                                    )
+                                    ),
+                                    encoding="utf-8",
                                 )
                                 break
                             except FileNotFoundError: