Revert "Fixed memory leak with cv method"

This reverts commit 77187bf.

Author: ankane

CHANGELOG.md

@@ -1,7 +1,3 @@
-## 0.4.4 (unreleased)
-
-- Fixed memory leak with `cv` method
-
 ## 0.4.3 (2025-06-26)
 
 - Added ARM shared library for Linux

lib/lightgbm/dataset.rb

@@ -183,7 +183,11 @@ def construct
 
         safe_call FFI.LGBM_DatasetCreateFromMat(c_data, FFI::C_API_DTYPE_FLOAT64, nrow, ncol, 1, parameters, reference, handle)
       end
-      @handle = ::FFI::AutoPointer.new(handle.read_pointer, FFI.method(:LGBM_DatasetFree))
+      if used_indices
+        @handle = handle.read_pointer
+      else
+        @handle = ::FFI::AutoPointer.new(handle.read_pointer, FFI.method(:LGBM_DatasetFree))
+      end
 
       self.label = @label if @label
       self.weight = @weight if @weight