Use IntEnum for convenience later

cal_tools/cal_tools/enums.py

-from enum import Enum
+from enum import Enum, IntEnum
 
 
 class BadPixels(Enum):
@@ -50,7 +50,7 @@ class SnowResolution(Enum):
     INTERPOLATE = "interpolate"
 
 
-class AgipdGainMode(Enum):
+class AgipdGainMode(IntEnum):
     """Encoding added to distinguish between adaptive and fixed gain"""
 
     ADAPTIVE_GAIN = 0  # adaptive is default (if gain mode missing in slow data)