Fix condition to check Arduino libraries cache

Author: Jason2866

builder/frameworks/component_manager.py

@@ -837,7 +837,7 @@ def _convert_lib_name_to_include(self, lib_name: str) -> str:
             Converted include directory name for path removal
         """
         # Load Arduino Core Libraries on first call
-        if not hasattr(self, '_arduino_libraries_cache'):
+        if self._arduino_libraries_cache is None:
             self._arduino_libraries_cache = self._get_arduino_core_libraries()
 
         lib_name_lower = lib_name.lower()