ExceptionGroups do not respect `__tracebackhide__`

[jakkdl]

repro:

def g1():
    __tracebackhide__ = True
    str.does_not_exist

def f3():
    __tracebackhide__ = True
    1 / 0

def f2():
    __tracebackhide__ = True
    exc = None
    try:
        f3()
    except Exception as e:
        exc = e
    exc2 = None
    try:
        g1()
    except Exception as e:
        exc2 = e
    raise ExceptionGroup("blah", [exc, exc2])


def f1():
    __tracebackhide__ = True
    f2()

def test():
    f1()

actual output:

____________________________________ test _____________________________________
  + Exception Group Traceback (most recent call last):
  |   File "/home/h/Git/pytest/hide_tb/foo.py", line 33, in test
  |     f1()
  |     ~~^^
  |   File "/home/h/Git/pytest/hide_tb/foo.py", line 30, in f1
  |     f2()
  |     ~~^^
  |   File "/home/h/Git/pytest/hide_tb/foo.py", line 25, in f2
  |     raise ExceptionGroup("blah", [exc, exc2])
  | ExceptionGroup: blah (2 sub-exceptions)
  +-+---------------- 1 ----------------
    | Traceback (most recent call last):
    |   File "/home/h/Git/pytest/hide_tb/foo.py", line 17, in f2
    |     f3()
    |     ~~^^
    |   File "/home/h/Git/pytest/hide_tb/foo.py", line 11, in f3
    |     f4()
    |     ~~^^
    |   File "/home/h/Git/pytest/hide_tb/foo.py", line 7, in f4
    |     1 / 0
    |     ~~^~~
    | ZeroDivisionError: division by zero
    +---------------- 2 ----------------
    | Traceback (most recent call last):
    |   File "/home/h/Git/pytest/hide_tb/foo.py", line 22, in f2
    |     g1()
    |     ~~^^
    |   File "/home/h/Git/pytest/hide_tb/foo.py", line 3, in g1
    |     str.does_not_exist
    | AttributeError: type object 'str' has no attribute 'does_not_exist'
    +------------------------------------

expected output

____________________________________ test _____________________________________
  + Exception Group Traceback (most recent call last):
  |   File "/home/h/Git/pytest/hide_tb/foo.py", line 33, in test
  |     f1()
  |     ~~^^
  | ExceptionGroup: blah (2 sub-exceptions)
  +-+---------------- 1 ----------------
    | ZeroDivisionError: division by zero
    +---------------- 2 ----------------
    | AttributeError: type object 'str' has no attribute 'does_not_exist'
    +------------------------------------

This is as much a feature request as it is a bug - the logic has simply not been implemented given that exception groups always fall back to displaying using tbstyle "native". See #9159

Designing the output of exception groups to be as pretty as the other "tbstyle"s would require a lot of design decisions, but a minimal implementation could keep the look of "native" except add features such as traceback filtering.