Fix None type not iterable issue on Github actions

Author: makermelissa

adafruit_platformdetect/__init__.py

@@ -61,7 +61,8 @@ def check_dt_compatible_value(self, value):
         otherwise False.
         """
         # Match a value like 'qcom,apq8016-sbc':
-        if value in self.get_device_compatible():
+        dt_compatible = self.get_device_compatible()
+        if dt_compatible and value in dt_compatible:
             return True
 
         return False