Add Skip test in TestTranschex (#8416)

Fixes #8415

Skip test if too many requests for huggingface hub to avoid block test.

### Types of changes
<!--- Put an `x` in all the boxes that apply, and remove the not
applicable items -->
- [x] Non-breaking change (fix or new feature that would not break
existing functionality).
- [ ] Breaking change (fix or new feature that would cause existing
functionality to change).
- [ ] New tests added to cover the changes.
- [ ] Integration tests passed locally by running `./runtests.sh -f -u
--net --coverage`.
- [ ] Quick tests passed locally by running `./runtests.sh --quick
--unittests --disttests`.
- [ ] In-line docstrings updated.
- [ ] Documentation updated, tested `make html` command in the `docs/`
folder.

Signed-off-by: YunLiu <55491388+KumoLiu@users.noreply.github.com>

Author: KumoLiu

tests/networks/nets/test_transchex.py

@@ -18,7 +18,7 @@
 
 from monai.networks import eval_mode
 from monai.networks.nets.transchex import Transchex
-from tests.test_utils import skip_if_quick
+from tests.test_utils import skip_if_downloading_fails, skip_if_quick
 
 TEST_CASE_TRANSCHEX = []
 for drop_out in [0.4]:
@@ -49,7 +49,8 @@
 class TestTranschex(unittest.TestCase):
     @parameterized.expand(TEST_CASE_TRANSCHEX)
     def test_shape(self, input_param, expected_shape):
-        net = Transchex(**input_param)
+        with skip_if_downloading_fails():
+            net = Transchex(**input_param)
         with eval_mode(net):
             result = net(torch.randint(2, (2, 512)), torch.randint(2, (2, 512)), torch.randn((2, 3, 224, 224)))
             self.assertEqual(result.shape, expected_shape)