Replace int(..) with torch.sym_int(...) for IR export compatibility (#3133)

Summary:

int(..) is not PT2 IR compatible

Reviewed By: TroyGarden

Differential Revision: D77195403

Author: jd7-tr

torchrec/sparse/jagged_tensor.py

@@ -1102,7 +1102,7 @@ def _maybe_compute_stride_kjt(
         elif (
             stride_per_key_per_rank is not None and stride_per_key_per_rank.numel() > 0
         ):
-            stride = int(stride_per_key_per_rank.sum(dim=1).max().item())
+            stride = torch.sym_int(stride_per_key_per_rank.sum(dim=1).max().item())
         elif offsets is not None and offsets.numel() > 0:
             stride = (offsets.numel() - 1) // len(keys)
         elif lengths is not None: