Added support for Enum types in Pydantic models

[AdilFayyaz]

Tracking issue

Duplicated from: flyteorg/flyte-sdk/pull/622

Why are the changes needed?

Ensure flytekit versions alongside flytesdk

What changes were proposed in this pull request?

In generate_attribute_list_from_dataclass_json_mixin(), when a $ref resolves to an enum definition (has enum key, no properties), map the field to str instead of trying to construct a dataclass from it. Previously this crashed with KeyError: 'properties' because the code assumed every $ref pointed to a model.

How was this patch tested?

Test (test_enum_in_pydantic.py): Defines a Job(BaseModel) with a Status(str, Enum) field, roundtrips it through to_literal_type -> to_literal -> to_python_value -> guess_python_type, and verifies the guessed dataclass accepts enum values as strings.

Setup process

Screenshots

Check all the applicable boxes

• I updated the documentation accordingly.
• All new and existing tests passed.
• All commits are signed-off.

Related PRs

Docs link

[codecov]

Codecov Report

❌ Patch coverage is 0% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 47.80%. Comparing base (ba7dc6f) to head (83826a5).

Files with missing lines	Patch %	Lines
flytekit/core/type_engine.py	0.00%	3 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           master    #3391       +/-   ##
===========================================
- Coverage   95.82%   47.80%   -48.02%     
===========================================
  Files           5      216      +211     
  Lines         527    22782    +22255     
  Branches        0     2998     +2998     
===========================================
+ Hits          505    10892    +10387     
- Misses         22    11295    +11273     
- Partials        0      595      +595     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.