Restore torch defaults between sgl-kernel tests (#11131)

sgl-kernel/tests/test_torch_defaults_reset.py

@@ -0,0 +1,16 @@
+import pytest
+import torch
+
+
+def test_change_torch_defaults():
+    torch.set_default_device("cpu:0")
+    torch.set_default_dtype(torch.float16)
+
+
+def test_check_torch_defaults():
+    assert torch.get_default_device() == torch.device("cpu")
+    assert torch.get_default_dtype() == torch.float32
+
+
+if __name__ == "__main__":
+    pytest.main([__file__])