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/dcs/aircrafttype.py

@@ -325,7 +325,7 @@ class AircraftType(UnitType[Type[FlyingType]]):
             logging.warning(f"No data for {aircraft.id}; it will not be available")
             return
 
-        with data_path.open() as data_file:
+        with data_path.open(encoding="utf-8") as data_file:
             data = yaml.safe_load(data_file)
 
         try:

game/dcs/groundunittype.py

@@ -67,7 +67,7 @@ class GroundUnitType(UnitType[Type[VehicleType]]):
             logging.warning(f"No data for {vehicle.id}; it will not be available")
             return
 
-        with data_path.open() as data_file:
+        with data_path.open(encoding="utf-8") as data_file:
             data = yaml.safe_load(data_file)
 
         try: