Periods in Budgets are show with incorrect dates #179
Description
For a budget period of "2025-05" its coming through as "2025-04-30" when in the New Zealand Timezone.
It appears that when usin DATE_WITH_NO_DAY_RE (https://github.com/XeroAPI/xero-python/blob/master/xero_python/api_client/deserializer.py) it adds a "-01" onto the date so appears as "2025-05-01" but when it returns the date is converted to UTC and therefore incorrectly gives the UTC date as "2025-04-30" when you are in a timezone which is forward of UTC
@deserialize.register("date[ms-format]")
def deserialize_date_ms(data_type, data, model_finder):
"""Deserializes data into a python date
Expected input value in format /Date(timestamp_in_milliseconds)/
Raise ValueError if the input is well formatted but not a valid date.
Return None if the input isn't well formatted.
:param data_type: class literal for deserialized object, or string of class name
:param data: data to be parsed
:param model_finder: ModelFinder instance to find class for data_type class literal
:return: deserialized datetime.date
"""
ms_datetime = deserialize_datetime_ms(data_type, data, model_finder)
# shift datetime to utc timezone to make sure utc date used
return ms_datetime.astimezone(tz=tz.UTC).date()