Add best.pt PyTorch Hub inference to CI (#8024)

.github/workflows/ci-testing.yml

@@ -114,4 +114,6 @@ jobs:
           import torch
           model = torch.hub.load('.', 'custom', path='$model', source='local')
           print(model('data/images/bus.jpg'))
+          model = torch.hub.load('.', 'custom', path='$best', source='local')
+          print(model('data/images/bus.jpg'))
           EOF