[R] remove XGBoosterPredict_R (fixes #8687) (#8689)

R-package/src/xgboost_R.cc

@@ -458,27 +458,6 @@ XGB_DLL SEXP XGBoosterEvalOneIter_R(SEXP handle, SEXP iter, SEXP dmats, SEXP evn
   return mkString(ret);
 }
 
-XGB_DLL SEXP XGBoosterPredict_R(SEXP handle, SEXP dmat, SEXP option_mask,
-                                SEXP ntree_limit, SEXP training) {
-  SEXP ret;
-  R_API_BEGIN();
-  bst_ulong olen;
-  const float *res;
-  CHECK_CALL(XGBoosterPredict(R_ExternalPtrAddr(handle),
-                              R_ExternalPtrAddr(dmat),
-                              asInteger(option_mask),
-                              asInteger(ntree_limit),
-                              asInteger(training),
-                              &olen, &res));
-  ret = PROTECT(allocVector(REALSXP, olen));
-  for (size_t i = 0; i < olen; ++i) {
-    REAL(ret)[i] = res[i];
-  }
-  R_API_END();
-  UNPROTECT(1);
-  return ret;
-}
-
 XGB_DLL SEXP XGBoosterPredictFromDMatrix_R(SEXP handle, SEXP dmat, SEXP json_config)  {
   SEXP r_out_shape;
   SEXP r_out_result;