Update CHANGELOG.md: add IncorrectOperationException fix to 4.2.1 section

Agent-Logs-Url: https://github.com/SeeSharpSoft/intellij-csv-validator/sessions/02fb7c80-41fd-4561-ac47-12924be00c20

Co-authored-by: SeeSharpSoft <3205800+SeeSharpSoft@users.noreply.github.com>

Author: Copilot

CHANGELOG.md

@@ -15,6 +15,7 @@
 ### Fixed
 
 - PluginException: Invalid PSI Element CsvFile when file is invalidated during annotation, intention actions, or inspection fixes
+- IncorrectOperationException: parent CsvTableEditorSwing already disposed when async PsiTreeChangeListener registration completes
 
 ## 4.2.0 - Jan 26, 2026