modify doc/conf.py, reflect changes in test file

Author: Tieqiong

doc/source/conf.py

@@ -18,6 +18,8 @@
 from importlib.metadata import version
 from pathlib import Path
 
+autodoc_mock_imports = ["importlib.metadata"]
+
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use Path().resolve() to make it absolute, like shown here.