Delete deletion-eligible test_swin_transformer_3d_encoder (#555)

Summary:
Pull Request resolved: #555

Oncall test cleanup for the `stl_multimodal` rotation. TestX flags
`TestSwinTransformer3d.test_swin_transformer_3d_encoder` (test IDs
`281475243855605` and `281475243659048`) as eligible for deletion — it sits in
`DISABLED_FAILING` trunk state with an open `FAILURE` issue, well past the
60-day zero-value threshold.

It asserted a hard-coded output magnitude (`247.14674` to two decimal places)
from a seeded forward pass, so it is deleted rather than re-baselined.

`test_swin_transformer_3d_scripting` remains and still exercises the same
`SwinTransformer3d` instance built in `setUp` by round-tripping it through
`torch.jit.script`, which keeps the encoder covered against construction and
tracing regressions.

___

Differential Revision: D114397067

fbshipit-source-id: cc9b99e4322996d6f02d834f1404fea93e182bc3

Author: twmoveon

tests/modules/encoders/test_swin_transformer_3d_encoder.py

@@ -33,12 +33,5 @@ def setUp(self):
             num_classes=None,
         ).to(self.device)
 
-    def test_swin_transformer_3d_encoder(self):
-        image = torch.randn(1, 3, 1, 112, 112)  # B C D H W
-
-        scores = self.encoder(image)
-        self.assertEqual(scores.size(), torch.Size([1, 768]))
-        self.assertAlmostEqual(scores.abs().sum().item(), 247.14674, 2)
-
     def test_swin_transformer_3d_scripting(self):
         torch.jit.script(self.encoder)