Remove obsolete RapidJSON tensor helper

Author: Reranko05

cpp/src/arrow/extension/tensor_internal.cc

@@ -30,20 +30,6 @@
 
 namespace arrow::internal {
 
-namespace {
-
-// Names indexed by rapidjson::Type enum value:
-// kNullType=0, kFalseType=1, kTrueType=2, kObjectType=3,
-// kArrayType=4, kStringType=5, kNumberType=6.
-constexpr const char* kJsonTypeNames[] = {"Null",  "False",  "True",  "Object",
-                                          "Array", "String", "Number"};
-
-}  // namespace
-
-const char* JsonTypeName(const ::arrow::rapidjson::Value& v) {
-  return kJsonTypeNames[v.GetType()];
-}
-
 Result<int64_t> ComputeShapeProduct(std::span<const int64_t> shape) {
   int64_t product = 1;
   for (const auto dim : shape) {

cpp/src/arrow/extension/tensor_internal.h

@@ -21,18 +21,11 @@
 #include <span>
 #include <vector>
 
-#include "arrow/json/rapidjson_defs.h"  // IWYU pragma: keep
 #include "arrow/result.h"
 #include "arrow/type_fwd.h"
 
-#include <rapidjson/document.h>
-
 namespace arrow::internal {
 
-/// \brief Return the name of a RapidJSON value's type (e.g., "Null", "Array", "Number").
-ARROW_EXPORT
-const char* JsonTypeName(const ::arrow::rapidjson::Value& v);
-
 /// \brief Compute the product of the given shape dimensions.
 ///
 /// Returns Status::Invalid if the product would overflow int64_t.