Fix compatibility with FastAPI>=0.128.0 (#59872)

As Cadwyn 6.0.0 is released with compatibility with FastAPI 0.128.0+,
we can now attempt to run the tests with it and see what else needs
to be fixed.

Related: zmievsa/cadwyn#316

Author: potiuk

airflow-core/pyproject.toml

@@ -77,20 +77,15 @@ dependencies = [
     "argcomplete>=1.10",
     "asgiref>=2.3.0",
     "attrs>=22.1.0, !=25.2.0",
-    "cadwyn>=5.6.2",
+    "cadwyn>=6.0.0",
     "colorlog>=6.8.2",
     "cron-descriptor>=1.2.24",
     "croniter>=2.0.2",
     # TODO(potiuk): We should bump cryptography to >=46.0.0 when sqlalchemy>=2.0 is required
     "cryptography>=41.0.0,<46.0.0",
     "deprecated>=1.2.13",
     "dill>=0.2.2",
-    # Cadwyn is not compatible with FastAPI 0.128.0 due to dropping of Pydantic v1 and Cadwyn using some
-    # internal methods dropped in FastAPI 0.128.0. Tracked in https://github.com/zmievsa/cadwyn/issues/316
-    # We will also have to fix `task-sdk/dev/generate_task_sdk_models.py` script as we are mocking removed
-    # _get_long_model_name method there once Cadwyn releases a new version - we should find a better way
-    # to override long model name (if it is still needed) without relying on private methods.
-    "fastapi[standard-no-fastapi-cloud-cli]>=0.127.0,<0.128.0",
+    "fastapi[standard-no-fastapi-cloud-cli]>=0.128.0",
     "uvicorn>=0.37.0",
     "starlette>=0.45.0",
     "httpx>=0.25.0",

task-sdk/dev/generate_task_sdk_models.py

@@ -20,7 +20,6 @@
 import os
 import sys
 from pathlib import Path
-from unittest import mock
 
 import httpx
 from datamodel_code_generator import (
@@ -76,7 +75,6 @@ def load_config():
     return cfg
 
 
-@mock.patch("fastapi._compat.v2.get_long_model_name", lambda model: model.__name__)
 def generate_file():
     from airflow.api_fastapi.execution_api.app import InProcessExecutionAPI