Update whats-new.txt

Author: rustagir

source/whats-new.txt

@@ -37,7 +37,7 @@ improvements, and fixes:
 
       the :atlas:`Atlas Vector Search Quick Start
       </atlas-vector-search/tutorials/vector-search-quick-start/>` and
-      select :guilabel:`Kotlin (Sync)` from the language dropdown.
+      select :guilabel:`Kotlin (Sync)` from the language dropdown
 
 - Adds support for serializers from the ``kotlinx-datetime`` library
   that let you map {+language+} date and time types to BSON as the