Fix issue with mutuable default value in dataclass parameter

[fredrikrab]

Use default_factory to initialize AnkiHookManager instead, solving the ValueError exception enforced since Python 3.11.

See https://docs.python.org/3/library/dataclasses.html#mutable-default-values.

I got the following error upon opening Anki prior to this commit:

When loading '⁨CrowdAnki JSON exportimport Edit history Collaborate on deck creation⁩':
⁨Traceback (most recent call last):
  File "/usr/lib/python3.11/site-packages/aqt/addons.py", line 246, in loadAddons
    __import__(addon.dir_name)
  File "/home/fredmb/.local/share/Anki2/addons21/1788670778/__init__.py", line 5, in <module>
    from . import main
  File "/home/fredmb/.local/share/Anki2/addons21/1788670778/main.py", line 8, in <module>
    from .anki.hook_vendor import HookVendor
  File "/home/fredmb/.local/share/Anki2/addons21/1788670778/anki/hook_vendor.py", line 13, in <module>
    @dataclass
     ^^^^^^^^^
  File "/usr/lib/python3.11/dataclasses.py", line 1223, in dataclass
    return wrap(cls)
           ^^^^^^^^^
  File "/usr/lib/python3.11/dataclasses.py", line 1213, in wrap
    return _process_class(cls, init, repr, eq, order, unsafe_hash,
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/dataclasses.py", line 958, in _process_class
    cls_fields.append(_get_field(cls, name, type, kw_only))
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/dataclasses.py", line 815, in _get_field
    raise ValueError(f'mutable default {type(f.default)} for field '
ValueError: mutable default <class '1788670778.anki.adapters.hook_manager.AnkiHookManager'> for field hook_manager is not allowed: use default_factory

⁩

[aplaice]

Thanks very much!

(I understand ArchLinux and/or other rolling-release distros are now using Python3.11?)

[fredrikrab]

Thank you as well :) Arch Linux is indeed hosting version 3.11 as the default Python package in their Core repo.

(It was upgraded on the same day as the official release!)

[Mxbonn]

Can we get a release and update on ankiweb for this @aplaice?