tests: update tests to use httpx.AsyncClient (#3984)

* Add async support and dependencies to pyproject.toml files

- Added `asgi-lifespan>=2.1.0` to dependencies.
- Configured `asyncio_mode` and `asyncio_default_fixture_loop_scope` for pytest.
- Updated `tool.uv` section with `asgi-lifespan` in dev-dependencies.

* Convert test fixtures to async and use AsyncClient for HTTP requests

* Handle 'ImportFrom' nodes in AST validation to support module attribute imports

* Convert test cases to use async HTTP client

- Updated test cases in `test_database.py`, `test_endpoints.py`, `test_user.py`, `test_variable.py`, `test_files.py`, `test_chat_endpoint.py`, `test_misc.py`, `test_messages_endpoints.py`, `test_api_key.py`, `test_webhook.py`, and `test_login.py` to use `httpx.AsyncClient` instead of `fastapi.TestClient`.
- Modified test functions to be asynchronous and use `await` for HTTP requests.
- Adjusted fixtures and helper functions to support asynchronous operations.
- Ensured consistency in endpoint paths and request methods across all test cases.

* Refactor string concatenation to f-string in test_chat_endpoint.py

* [autofix.ci] apply automated fixes

* Refactor import validation to use pattern matching for AST nodes

* Set `startup_timeout` and `shutdown_timeout` to `None` in `LifespanManager` for test files.

* Convert test functions to async in `test_messages_endpoints.py`

* Add `api_key_required` marker to assistant component tests

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

pyproject.toml

@@ -301,8 +301,8 @@ dev-dependencies = [
     "pytest-split>=0.9.0",
     "pytest-flakefinder>=1.1.0",
     "types-markdown>=3.7.0.20240822",
-    "packaging>=23.2,<24.0"
-
+    "packaging>=23.2,<24.0",
+    "asgi-lifespan>=2.1.0",
 ]
 
 
@@ -328,7 +328,8 @@ log_cli = true
 log_cli_format = "%(asctime)s [%(levelname)8s] %(message)s (%(filename)s:%(lineno)s)"
 log_cli_date_format = "%Y-%m-%d %H:%M:%S"
 markers = ["async_test", "api_key_required"]
-
+asyncio_mode = "auto"
+asyncio_default_fixture_loop_scope = "function"
 
 [tool.coverage.run]
 command_line = """
@@ -365,4 +366,4 @@ ignore_missing_imports = true
 
 [build-system]
 requires = ["hatchling"]
-build-backend = "hatchling.build"
+build-backend = "hatchling.build"