idle doesn't display nested tracebacks for ExceptionGroups

[graingert]

Bug report

Bug description:

Idle prints:

Python 3.13.0a1+ (main, Oct 20 2023, 08:50:56) [GCC 11.4.0] on linux
Type "help", "copyright", "credits" or "license()" for more information.
raise ExceptionGroup("bad", [ValueError()])
Traceback (most recent call last):
  File "<pyshell#0>", line 1, in <module>
    raise ExceptionGroup("bad", [ValueError()])
ExceptionGroup: bad (1 sub-exception)

the repl displays tracebacks correctly:

Python 3.13.0a1+ (main, Oct 20 2023, 08:50:56) [GCC 11.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> raise ExceptionGroup("bad", [ValueError()])
  + Exception Group Traceback (most recent call last):
  |   File "<stdin>", line 1, in <module>
  |     raise ExceptionGroup("bad", [ValueError()])
  | ExceptionGroup: bad (1 sub-exception)
  +-+---------------- 1 ----------------
    | ValueError
    +------------------------------------ 

CPython versions tested on:

3.12, 3.13

Operating systems tested on:

Linux

[graingert]

here's where the traceback is cleaned and printed:

cpython/Lib/idlelib/run.py

Lines 261 to 266 in 9d4a1a4

	tbe = traceback.extract_tb(tb)
	print('Traceback (most recent call last):', file=efile)
	exclude = ("run.py", "rpc.py", "threading.py", "queue.py",
	"debugger_r.py", "bdb.py")
	cleanup_traceback(tbe, exclude)
	traceback.print_list(tbe, file=efile)