When trying to import hydra in Python 3.11, it throws following error:
```python
  File "/home/user/projects/iterative/hydra/hydra/conf/__init__.py", line 75, in JobConf
    @DataClass
     ^^^^^^^^^
  File "/home/user/.pyenv/versions/3.11-dev/lib/python3.11/dataclasses.py", line 1221, in dataclass
    return wrap(cls)
           ^^^^^^^^^
  File "/home/user/.pyenv/versions/3.11-dev/lib/python3.11/dataclasses.py", line 1211, in wrap
    return _process_class(cls, init, repr, eq, order, unsafe_hash,
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user/.pyenv/versions/3.11-dev/lib/python3.11/dataclasses.py", line 959, in _process_class
    cls_fields.append(_get_field(cls, name, type, kw_only))
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user/.pyenv/versions/3.11-dev/lib/python3.11/dataclasses.py", line 816, in _get_field
    raise ValueError(f'mutable default {type(f.default)} for field '
ValueError: mutable default <class 'hydra.conf.JobConf.JobConfig.OverrideDirname'> for field override_dirname is not allowed: use default_factory
```

This is due to a recent change in dataclasses in Python 3.11 that
disallows mutable to be set as a default value. This is done
via check for hashability.

See python/cpython#88840.
Note that I am trying to add support for Python 3.11 to hydra. This
seems like a major blocker.

For reproducibility, I used the following command to search for these:
```console
rg ".*: .* = [A-Z].*\(.*\)"
```