Fix undefined names in Python code (#2371)

Co-authored-by: Andrea Giammarchi <andrea.giammarchi@gmail.com>

core/tests/javascript/terminal.py

@@ -2,7 +2,7 @@ from pyscript import document
 
 classList = document.documentElement.classList
 
-if not __terminal__:
+if not __terminal__:  # noqa: F821  __terminal__ is defined in core/src/plugins/donkey.js
     classList.add("error")
 else:
     classList.add("ok")