test: re-enable model generation test on Python 3.15 (#1204)

datamodel-code-generator supports Python 3.15 since 0.85.0
(datamodel-code-generator/datamodel-code-generator#4609), so the 3.15 skip on
`test_model_generation_pipeline` can go. The dev dependency floor moves
to `>=0.85.0`; the lockfile already pins 0.87.0.

Closes: #1127

*✍️ Drafted by Claude Code*

Author: vdusek

pyproject.toml

@@ -53,7 +53,7 @@ dev = [
     # See https://github.com/apify/apify-client-python/pull/582/ for more details.
     # We explicitly constrain black>=24.3.0 to override the transitive dependency.
     "black>=24.3.0",
-    "datamodel-code-generator[http,ruff]>=0.64.1,<1.0.0",
+    "datamodel-code-generator[http,ruff]>=0.85.0,<1.0.0",
     "griffe<3.0.0",
     "poethepoet<1.0.0",
     "pre-commit<5.0.0",

tests/unit/test_model_generation.py

@@ -5,8 +5,6 @@
 import sys
 from typing import TYPE_CHECKING
 
-import pytest
-
 from scripts.postprocess_generated_models import (
     REPO_ROOT,
     RESOURCE_INPUT_TYPEDDICTS,
@@ -58,10 +56,6 @@ def run_datamodel_codegen(*args: str) -> None:
     )
 
 
-@pytest.mark.skipif(
-    sys.version_info >= (3, 15),
-    reason='datamodel-code-generator fails to import on Python 3.15 (koxudaxi/datamodel-code-generator#4609)',
-)
 def test_model_generation_pipeline(tmp_path: Path) -> None:
     """The `generate-models` pipeline (both codegen passes and post-processing) runs on a minimal spec."""
     # PR CI never runs `poe generate-models`, so this catches a dependency update that breaks the generator.