Open all files with utf-8 encoding

- will not be used for binary read/writes (rb,wb)!
- prevents a bug where units with special characters in the unit name can not be tracked anymore as there will be a name mismatch due to wrong encoding

game/version.py

@@ -12,7 +12,7 @@ def _build_version_string() -> str:
     ]
     build_number_path = Path("resources/buildnumber")
     if build_number_path.exists():
-        with build_number_path.open("r") as build_number_file:
+        with build_number_path.open("r", encoding="utf-8") as build_number_file:
             components.append(build_number_file.readline())
 
     if not Path("resources/final").exists():