Update changelog for v0.5.0 rc2 (#1624)

Author: chuneuny-emily

CHANGELOG.md

@@ -24,6 +24,7 @@ All notable changes to this project will be documented in this file.
 - Fixing tiling OpenVINO backward compatibility (<https://github.com/openvinotoolkit/training_extensions/pull/1516>)
 - Fixing indexing in hierarchical classification inference (<https://github.com/openvinotoolkit/training_extensions/pull/1551>)
 - Copying feature vector to resolve duplication issue (<https://github.com/openvinotoolkit/training_extensions/pull/1511>)
+- Fixing handling ignored samples in hierarchical head (<https://github.com/openvinotoolkit/training_extensions/pull/1599>)
 - Some minor issues
 
 ## \[v0.4.0\]