Moved busio imports inside a try block to save memory

Author: tammymakesthings

adafruit_amg88xx.py

@@ -28,13 +28,14 @@
 
 from adafruit_bus_device.i2c_device import I2CDevice
 from adafruit_register import i2c_bit, i2c_bits
-from adafruit_register.i2c_bits import RWBits
-from adafruit_register.i2c_bit import RWBit
 from micropython import const
-import busio
 
 try:
     from typing import List
+    # These are only needed for typing
+    import busio  # pylint: disable=unused-import
+    from adafruit_register.i2c_bits import RWBits  # pylint: disable=unused-import,line-too-long
+    from adafruit_register.i2c_bit import RWBit  # pylint: disable=unused-import,line-too-long
 except ImportError:
     pass