gh-131741: Fix code review notes

* Removed bullet point present in full changelog
* Changed backticks to RST format (` -> ``)
* Grammar changes ("Prior" -> "Previously")

Author: idann

Doc/whatsnew/3.12.rst

@@ -815,13 +815,10 @@ platform
 --------
 
 * Add support for detecting Windows 11 and Windows Server releases past 2012.
-  Prior, lookups on Windows Server platforms newer than Windows Server 2012
-  and on Windows 11 would return `Windows-10`.
+  Previously, lookups on Windows Server platforms newer than Windows Server 2012
+  and on Windows 11 would return ``Windows-10``.
   (Contributed by Steve Dower in :gh:`89545`.)
 
-* Add support for detecting Windows Server 2025.
-  (Contributed by Wulian233 in :gh:`127732`.)
-
 pdb
 ---