Upgrading from spaCy 2.x to 3.x: Handling KeyError for ArabicDefaults.lex_attr_getters[NORM]

[pkganas]

from spacy.attrs import NORM, LANG
from spacy.lang.ar import ArabicDefaults, Arabic

class CustomArabicDefaults(ArabicDefaults):
    lex_attr_getters = dict(ArabicDefaults.lex_attr_getters)
    lex_attr_getters[LANG] = lambda text: "ar"  # language ISO code
    lex_attr_getters[NORM] = lambda x: normalize_arabic(
        ArabicDefaults.lex_attr_getters[NORM](x)
    )


# Create actual Language class
class CustomArabicBase(Arabic):
    lang = "ar"  # Language ISO code
    Defaults = CustomArabicDefaults  # Override default

I'm upgrading the above class from spaCy 2.x to 3.x and encountering an issue with custom normalization. In spaCy 2.x, the code ArabicDefaults.lex_attr_getters[NORM](x) worked fine. However, in spaCy 3.x, it throws a KeyError because spacy.attrs.NORM is 67, but ArabicDefaults.lex_attr_getters no longer has the key 67. Instead, it returns a dictionary with key 10 which maps to the like_num function.

I'm not very experienced with spaCy, and I would appreciate any help on how to rewrite this class for spaCy 3.x while maintaining the custom normalization functionality.

Thanks in advance!