python-proto-plus cannot build properly under Python 3.11:

+ /usr/bin/pytest
============================= test session starts ==============================
platform linux -- Python 3.11.0b3, pytest-7.1.2, pluggy-1.0.0
rootdir: /builddir/build/BUILD/proto-plus-python-1.20.6
collected 253 items

tests/test_datetime_helpers.py ................................          [ 12%]
tests/test_enum_total_ordering.py .F.....                                [ 15%]
tests/test_fields_bytes.py .....                                         [ 17%]
tests/test_fields_composite.py ......                                    [ 19%]
tests/test_fields_composite_string_ref.py .....                          [ 21%]
tests/test_fields_enum.py ...................F                           [ 29%]
tests/test_fields_int.py .......                                         [ 32%]
tests/test_fields_map_composite.py .....                                 [ 34%]
tests/test_fields_map_scalar.py ....                                     [ 35%]
tests/test_fields_mitigate_collision.py .                                [ 36%]
tests/test_fields_oneof.py ..                                            [ 37%]
tests/test_fields_optional.py ..                                         [ 37%]
tests/test_fields_repeated_composite.py ...................              [ 45%]
tests/test_fields_repeated_scalar.py ..........                          [ 49%]
tests/test_fields_string.py ...                                          [ 50%]
tests/test_file_info_salting.py ..                                       [ 51%]
tests/test_file_info_salting_with_manifest.py ..                         [ 52%]
tests/test_json.py .........                                             [ 55%]
tests/test_marshal_register.py ...                                       [ 56%]
tests/test_marshal_strict.py .                                           [ 57%]
tests/test_marshal_stringy_numbers.py ...................                [ 64%]
tests/test_marshal_types_dates.py ................                       [ 71%]
tests/test_marshal_types_enum.py .....                                   [ 73%]
tests/test_marshal_types_message.py ..                                   [ 73%]
tests/test_marshal_types_struct.py .......................               [ 83%]
tests/test_marshal_types_wrappers_bool.py ........                       [ 86%]
tests/test_message.py .........................                          [ 96%]
tests/test_message_filename.py .                                         [ 96%]
tests/test_message_filename_with_and_without_manifest.py .               [ 96%]
tests/test_message_filename_with_manifest.py .                           [ 97%]
tests/test_message_nested.py ...                                         [ 98%]
tests/test_message_pickling.py .                                         [ 98%]
tests/test_modules.py ...                                                [100%]

=================================== FAILURES ===================================
____________________ test_total_ordering_w_other_enum_type _____________________

    def test_total_ordering_w_other_enum_type():
        to_compare = enums_test.OneEnum.SOME_VALUE
    
        for item in enums_test.OtherEnum:
            assert not to_compare == item
>           assert to_compare.SOME_VALUE != item

tests/test_enum_total_ordering.py:52: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <enum.property object at 0x7f48b7191c90>
instance = <OneEnum.SOME_VALUE: 1>, ownerclass = <enum 'OneEnum'>

    def __get__(self, instance, ownerclass=None):
        if instance is None:
            try:
                return ownerclass._member_map_[self.name]
            except KeyError:
                raise AttributeError(
                        '%r has no attribute %r' % (ownerclass, self.name)
                        )
        else:
            if self.fget is None:
>               raise AttributeError(
                        '%r member has no attribute %r' % (ownerclass, self.name)
                        )
E               AttributeError: <enum 'OneEnum'> member has no attribute 'SOME_VALUE'

/usr/lib64/python3.11/enum.py:198: AttributeError
_____________________________ test_enum_alias_good _____________________________

    def test_enum_alias_good():
        # Have to split good and bad enum alias into two tests so that the generated
        # file descriptor is properly created.
        # For the python runtime, aliases are allowed by default, but we want to
        # make sure that the options don't cause problems.
        # For the cpp runtime, we need to verify that we can in fact define aliases.
>       class GoodMessage(proto.Message):

tests/test_fields_enum.py:386: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
tests/test_fields_enum.py:387: in GoodMessage
    class GoodEnum(proto.Enum):
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

mcls = <class 'proto.enums.ProtoEnumMeta'>, name = 'GoodEnum'
bases = (<enum 'Enum'>,)
attrs = {'_generate_next_value_': <function Enum._generate_next_value_ at 0x7f48b7c4b4c0>, '__module__': 'test_fields_enum', '__qualname__': 'test_enum_alias_good.<locals>.GoodMessage.GoodEnum', 'UNKNOWN': 0, 'DEFAULT': 0}

    def __new__(mcls, name, bases, attrs):
        # Do not do any special behavior for `proto.Enum` itself.
        if bases[0] == enum.IntEnum:
            return super().__new__(mcls, name, bases, attrs)
    
        # Get the essential information about the proto package, and where
        # this component belongs within the file.
        package, marshal = _package_info.compile(name, attrs)
    
        # Determine the local path of this proto component within the file.
        local_path = tuple(attrs.get("__qualname__", name).split("."))
    
        # Sanity check: We get the wrong full name if a class is declared
        # inside a function local scope; correct this.
        if "<locals>" in local_path:
            ix = local_path.index("<locals>")
            local_path = local_path[: ix - 1] + local_path[ix + 1 :]
    
        # Determine the full name in protocol buffers.
        full_name = ".".join((package,) + local_path).lstrip(".")
        filename = _file_info._FileInfo.proto_file_name(
            attrs.get("__module__", name.lower())
        )
    
        # Retrieve any enum options.
        # We expect something that looks like an EnumOptions message,
        # either an actual instance or a dict-like representation.
        pb_options = "_pb_options"
        opts = attrs.pop(pb_options, {})
        # This is the only portable way to remove the _pb_options name
        # from the enum attrs.
        # In 3.7 onwards, we can define an _ignore_ attribute and do some
        # mucking around with that.
        if pb_options in attrs._member_names:
>           idx = attrs._member_names.index(pb_options)
E           AttributeError: 'dict' object has no attribute 'index'

../../BUILDROOT/python-proto-plus-1.20.6-1.fc37.x86_64/usr/lib/python3.11/site-packages/proto/enums.py:61: AttributeError
=========================== short test summary info ============================
FAILED tests/test_enum_total_ordering.py::test_total_ordering_w_other_enum_type
FAILED tests/test_fields_enum.py::test_enum_alias_good - AttributeError: 'dic...
======================== 2 failed, 251 passed in 0.96s =========================