"Exception ignored" is not produced by IDLE, and we have seen this before. multicall, line 29 says:

# In 3.4, if no shell window is ever open, the underlying Tk widget is
# destroyed before .__del__ methods here are called.  The following
# is used to selectively ignore shutdown exceptions to avoid
# 'Exception ignored' messages.  See http://bugs.python.org/issue20167
APPLICATION_GONE = "application has been destroyed"

For #20167, the object, condensed traceback, and exception were different, but the format was the same.  The check is in __del__, line 63.  This 'sweep the problem under the rug' fix was suggested by Tal and committed by me in 2014 for 3.4.  I hypothesized then that is had something to do with Python shutdown changing.

Before 3.8 releases, we should either sweep this and #37751 under the rug also, or take a good look at shutdown and try to fix it.