Upgrade dev dependencies and fix tests to support pytest-asyncio strict mode

tests/compute/virtualbox/test_virtualbox_manager.py

@@ -17,6 +17,7 @@
 
 
 import pytest
+import pytest_asyncio
 import tempfile
 import os
 import stat
@@ -28,7 +29,7 @@ from gns3server.compute.virtualbox.virtualbox_error import VirtualBoxError
 from tests.utils import asyncio_patch
 
 
-@pytest.fixture
+@pytest_asyncio.fixture
 async def manager(port_manager):
 
     m = VirtualBox.instance()