fix version number typo (#475)

Author: jeff-allen-mongo

source/release-notes/5.2-compatibility.txt

@@ -14,7 +14,7 @@ Compatibility Changes in MongoDB 5.2
 
 .. include:: /includes/rapid-release-short.rst
 
-The following 5.1 changes can affect compatibility with older versions
+The following 5.2 changes can affect compatibility with older versions
 of MongoDB.
 
 Removed Parameters