Add custom_attributes field support to User model

[Copilot]

Problem

When calling list_users2() from the UsersV2Api, the custom_attributes field was not accessible on the returned User objects, even though the OneLogin API includes this data in responses. Users had to resort to workarounds like:

# Workaround - accessing raw data
response = user_instance.list_users2_with_http_info(
    fields="id,email,custom_attributes"
).raw_data

This issue occurred because the custom_attributes field was not defined in the User model (onelogin/models/user.py).

Solution

Added custom_attributes as an optional dictionary field to the User model. Custom attributes are dynamic key-value pairs defined per OneLogin account, so they're represented as Optional[Dict[str, Any]].

Changes:

• Added custom_attributes field to the User model with proper type annotations
• Updated the __properties list to include the new field
• Modified from_dict() to parse custom_attributes from API responses
• Added documentation for the field in docs/User.md
• Created comprehensive test suite to validate the implementation

Usage

After this fix, custom attributes are directly accessible:

users = user_instance.list_users2()
for user in users:
    if user.custom_attributes:
        employee_id = user.custom_attributes.get('employee_id')
        department = user.custom_attributes.get('department_code')
        cost_center = user.custom_attributes.get('cost_center')

Testing

• ✅ All 335 existing tests pass (no regressions)
• ✅ Added 4 new tests specifically for custom_attributes functionality
• ✅ Validated with both UsersV1Api and UsersV2Api compatibility
• ✅ Manual testing confirms proper serialization and deserialization

Fixes #107

Original prompt

---

This section details on the original issue you should resolve

<issue_title>custom_attributes not working with UsersV2Api</issue_title>
<issue_description>Hi,

When executing the examples 'user_instance.list_users2()' it does not provide the 'custom_attributes'.

The only way I manage to get these is with 'user_instance.list_users2_with_http_info(fields="id,email,custom_attributes").raw_data'.

I noticed custom_attributes is not defined in models/user.py, so probably related to this?</issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes #109

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[Copilot]

Pull Request Overview

This PR adds support for the custom_attributes field to the User model to resolve an issue where users could not access custom attributes from the UsersV2Api responses despite the data being present in the API response.

• Added custom_attributes as an optional dictionary field to the User model
• Updated serialization/deserialization methods to handle the new field
• Created comprehensive test suite to validate the implementation

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
onelogin/models/user.py	Added custom_attributes field with proper type annotations and updated serialization methods
docs/User.md	Added documentation for the new custom_attributes field
test/test_user_custom_attributes.py	Added comprehensive test suite covering various scenarios for custom_attributes functionality

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