chore: remove dangling git merge issue from changelog

Author: vkarpov15

CHANGELOG.md

@@ -26,7 +26,6 @@
 6.13.6 / 2025-01-13
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  * fix: disallow nested $where in populate match CVE-2025-23061
-<<<<<<< HEAD
 
 8.9.4 / 2025-01-09
 ==================