chore: Try fix doc build

Author: SilverRainZ

docs/conf.py

@@ -134,9 +134,11 @@
 intersphinx_mapping['sphinx'] = ('https://www.sphinx-doc.org/en/master', None)
 intersphinx_mapping['data'] = ('https://sphinx.silverrainz.me/data', None)
 
+ctxdir_usage_example_path = os.path.abspath('../tests/roots/test-ctxdir-usage')
+
 def setup(app):
     app.add_object_type('event', 'event') # for intersphinx
 
-    sys.path.insert(0, os.path.abspath('../tests/roots/test-ctxdir-usage'))
+    sys.path.insert(0, ctxdir_usage_example_path)
     from conf import setup as setup_ctxdir_usage_example
     setup_ctxdir_usage_example(app)