fix(tests): Revert conftest.py and oauth_test.py fixture scope changes

The pytest_asyncio fixture changes with loop_scope="session" caused
"Event loop is closed" errors in all 31 oauth_test.py tests on CI.
MCP tests have their own conftest override and don't need these changes.

autogpt_platform/backend/backend/api/features/oauth_test.py

@@ -20,7 +20,6 @@ from typing import AsyncGenerator
 
 import httpx
 import pytest
-import pytest_asyncio
 from autogpt_libs.api_key.keysmith import APIKeySmith
 from prisma.enums import APIKeyPermission
 from prisma.models import OAuthAccessToken as PrismaOAuthAccessToken
@@ -39,13 +38,13 @@ keysmith = APIKeySmith()
 # ============================================================================
 
 
-@pytest.fixture(scope="session")
+@pytest.fixture
 def test_user_id() -> str:
     """Test user ID for OAuth tests."""
     return str(uuid.uuid4())
 
 
-@pytest_asyncio.fixture(scope="session", loop_scope="session")
+@pytest.fixture
 async def test_user(server, test_user_id: str):
     """Create a test user in the database."""
     await PrismaUser.prisma().create(
@@ -68,7 +67,7 @@ async def test_user(server, test_user_id: str):
     await PrismaUser.prisma().delete(where={"id": test_user_id})
 
 
-@pytest_asyncio.fixture(loop_scope="session")
+@pytest.fixture
 async def test_oauth_app(test_user: str):
     """Create a test OAuth application in the database."""
     app_id = str(uuid.uuid4())
@@ -123,7 +122,7 @@ def pkce_credentials() -> tuple[str, str]:
     return generate_pkce()
 
 
-@pytest_asyncio.fixture(loop_scope="session")
+@pytest.fixture
 async def client(server, test_user: str) -> AsyncGenerator[httpx.AsyncClient, None]:
     """
     Create an async HTTP client that talks directly to the FastAPI app.
@@ -288,7 +287,7 @@ async def test_authorize_invalid_client_returns_error(
     assert query_params["error"][0] == "invalid_client"
 
 
-@pytest_asyncio.fixture(loop_scope="session")
+@pytest.fixture
 async def inactive_oauth_app(test_user: str):
     """Create an inactive test OAuth application in the database."""
     app_id = str(uuid.uuid4())
@@ -1005,7 +1004,7 @@ async def test_token_refresh_revoked(
     assert "revoked" in response.json()["detail"].lower()
 
 
-@pytest_asyncio.fixture(loop_scope="session")
+@pytest.fixture
 async def other_oauth_app(test_user: str):
     """Create a second OAuth application for cross-app tests."""
     app_id = str(uuid.uuid4())

autogpt_platform/backend/backend/conftest.py

@@ -1,7 +1,7 @@
 import logging
 import os
 
-import pytest_asyncio
+import pytest
 from dotenv import load_dotenv
 
 from backend.util.logging import configure_logging
@@ -19,7 +19,7 @@ if not os.getenv("PRISMA_DEBUG"):
     prisma_logger.setLevel(logging.INFO)
 
 
-@pytest_asyncio.fixture(scope="session", loop_scope="session")
+@pytest.fixture(scope="session")
 async def server():
     from backend.util.test import SpinTestServer
 
@@ -27,7 +27,7 @@ async def server():
         yield server
 
 
-@pytest_asyncio.fixture(scope="session", loop_scope="session", autouse=True)
+@pytest.fixture(scope="session", autouse=True)
 async def graph_cleanup(server):
     created_graph_ids = []
     original_create_graph = server.agent_server.test_create_graph