Here's the problem: https://github.com/python/cpython/blob/main/Lib/test/test_enum.py#L4515-L4531

Why it is a problem?
1. First test is marked as `@unittest.skipUnless(python_version == (3, 8)`. Which means it is only executed on `3.8`. I think it should be removed from more recent branches
2. Second test is marked as `@unittest.skipUnless(python_version >= (3, 9)`. Which means that it will be executed on three currently supported branches. I think we can remove this decorator

I will send a PR today.

On the other hand second test 

```python
@unittest.skipUnless(python_version >= (3, 9),
                         '_convert was removed in 3.9')
    def test_convert_raise(self):
        with self.assertRaises(AttributeError):
            enum.IntEnum._convert(
                'UnittestConvert',
                MODULE,
                filter=lambda x: x.startswith('CONVERT_TEST_'))
```

can also be removed if needed.

New changeset 13e4659276c2af2fa5b0f2b3a31dcd69064868ef by Nikita Sobolev in branch 'main':
bpo-46327: [Enum] remove skipped tests (GH-30512)
https://github.com/python/cpython/commit/13e4659276c2af2fa5b0f2b3a31dcd69064868ef