Bug fix: Optional sequences shouldn't be defaulted to null

MLArgMinMaxOptions and MLReduceOptions have an 'axes' member that the
IDL declares as defaulting to null. They have type sequence<unsigned
long> which is not nullable. The intent is that these are optional
members with default behavior if not present, which is handled in the
algorithm already.

Author: inexorabletash

index.bs

@@ -1480,7 +1480,7 @@ Return the index location of the minimum or maxmium values of all the input valu
 
 <script type=idl>
 dictionary MLArgMinMaxOptions {
-  sequence<unsigned long> axes = null;
+  sequence<unsigned long> axes;
   boolean keepDimensions = false;
   boolean selectLastIndex = false;
 };
@@ -4917,7 +4917,7 @@ partial interface MLGraphBuilder {
 Reduce the input tensor along all dimensions, or along the axes specified in the {{MLReduceOptions/axes}}  array parameter. For each specified axis, the dimension with that index is reduced, i.e. the resulting tensor will not contain it, unless the {{MLReduceOptions/keepDimensions}} option is specified. The values of the resulting tensor are calculated using the specified reduction function that takes as parameters all the values across the reduced dimension.
 <script type=idl>
 dictionary MLReduceOptions {
-  sequence<unsigned long> axes = null;
+  sequence<unsigned long> axes;
   boolean keepDimensions = false;
 };