[mlir][sparse] Removing unused helper function

[wrengr]

Summary

Depends On D151505

mlir/lib/Dialect/SparseTensor/IR/SparseTensorDialect.cpp

 
 #define GET_TYPEDEF_CLASSES
 #include "mlir/Dialect/SparseTensor/IR/SparseTensorTypes.cpp.inc"
 
 using namespace mlir;
 using namespace mlir::sparse_tensor;
 
 //===----------------------------------------------------------------------===//
-// Additional convenience methods.
-//===----------------------------------------------------------------------===//
-
-/// Gets the dimension-rank of the type of some `T`.  (In particular
-/// this is only used for `Value` and `TypedValue<RankedTensorType>`.)
-template <typename T>
-static inline Dimension getDimRank(T t) {
-  return getRankedTensorType(t).getRank();
-}
-
-//===----------------------------------------------------------------------===//
 // StorageLayout
 //===----------------------------------------------------------------------===//
 
 static constexpr Level kInvalidLevel = -1u;
 static constexpr Level kInvalidFieldIndex = -1u;
 static constexpr FieldIndex kDataFieldStartingIdx = 0;
 
 void StorageLayout::foreachField(