Handle case when ald is not defined

Author: Jason2866

builder/frameworks/component_manager.py

@@ -52,7 +52,9 @@ def __init__(self, env):
         # Get Arduino libraries installation directory
         ald = self.platform.get_package_dir("framework-arduinoespressif32-libs")
         # Get MCU-specific Arduino libraries directory
-        self.arduino_libs_mcu = (str(Path(ald) / self.mcu))
+        self.arduino_libs_mcu = (
+            str(Path(ald) / self.mcu) if ald else ""
+        )
 
 
 class ComponentLogger: