[Bug]: Tests fail with pydantic 2.14.0 and kubernetes 37.0.0 (freezegun) #4357

Steps to reproduce

With pydantic 2.14.0, kubernetes 37.0.0 and freezegun 1.5.5 (a fresh uv sync --all-extras):

import kubernetes.client  # noqa: F401
from freezegun import freeze_time

with freeze_time("2026-01-01"):
    pass

Actual behaviour

PydanticSchemaGenerationError: Unable to generate pydantic-core schema for <class 'freezegun.api.FakeDatetime'>.

Root cause: pydantic 2.14.0 can't define a model with a datetime field while freezegun is active. It matches field types against the real datetime.datetime captured at import (pydantic#13573), but freezegun replaces datetime.datetime with FakeDatetime.

kubernetes 37.0.0 triggers this: kubernetes.client now imports its pydantic models lazily on attribute access, and freeze_time reads every attribute of every loaded module when it starts, so these models get defined while frozen. The error escapes freeze_time and leaves the clock frozen, so other tests in the same worker fail too.

Expected behaviour

Tests pass.

dstack version

master (2b4c065)

Notes

Only affects tests.

Workaround, verified with the full suite (3 of 3 runs green):

# src/tests/conftest.py
import freezegun

# Workaround for https://github.com/dstackai/dstack/issues/4357
freezegun.configure(extend_ignore_list=["kubernetes"])

It only stops freezegun from scanning kubernetes. The proper fix is replacing freezegun with time-machine, which doesn't swap datetime.datetime.