shapex.ranked_broadcast_in_dim: Make broadcast_dimensions non-optional

PiperOrigin-RevId: 306662871
diff --git a/iree/compiler/Dialect/Shape/IR/ShapeOps.td b/iree/compiler/Dialect/Shape/IR/ShapeOps.td
index 64c1c6a..26ec1c8 100644
--- a/iree/compiler/Dialect/Shape/IR/ShapeOps.td
+++ b/iree/compiler/Dialect/Shape/IR/ShapeOps.td
@@ -307,7 +307,7 @@
 
   let arguments = (ins AnyRankedTensor:$operand,
                        Shape_RankedShape:$result_shape,
-                       OptionalAttr<I64ElementsAttr>:$broadcast_dimensions);
+                       I64ElementsAttr:$broadcast_dimensions);
   let results = (outs AnyRankedTensor:$result);
 
   // TODO: Custom parser/printer