fix(typing): Ignore [arg-type] error in _deduplicate_enum_errors (#3475)

* fix(typing): Confirm arg type before joining in `_deduplicate_enum_errors`

Fixes `mypy` error that appeared during a merge #3467 (comment)

* revert: undo last commit

* revert: Ignore type error introduced by `typeshed`

The issue is not related to any runtime changes python-jsonschema/jsonschema#1019 (comment)

Author: dangotbanned

altair/utils/schemapi.py

@@ -420,7 +420,7 @@ def _deduplicate_enum_errors(errors: ValidationErrorList) -> ValidationErrorList
         # Values (and therefore `validator_value`) of an enum are always arrays,
         # see https://json-schema.org/understanding-json-schema/reference/generic.html#enumerated-values
         # which is why we can use join below
-        value_strings = [",".join(err.validator_value) for err in errors]
+        value_strings = [",".join(err.validator_value) for err in errors]  # type: ignore
         longest_enums: ValidationErrorList = []
         for value_str, err in zip(value_strings, errors):
             if not _contained_at_start_of_one_of_other_values(value_str, value_strings):

tools/schemapi/schemapi.py

@@ -418,7 +418,7 @@ def _deduplicate_enum_errors(errors: ValidationErrorList) -> ValidationErrorList
         # Values (and therefore `validator_value`) of an enum are always arrays,
         # see https://json-schema.org/understanding-json-schema/reference/generic.html#enumerated-values
         # which is why we can use join below
-        value_strings = [",".join(err.validator_value) for err in errors]
+        value_strings = [",".join(err.validator_value) for err in errors]  # type: ignore
         longest_enums: ValidationErrorList = []
         for value_str, err in zip(value_strings, errors):
             if not _contained_at_start_of_one_of_other_values(value_str, value_strings):