DOCSP-29819: type regression issue fixed in 4.8.1 (#688)

* DOCSP-29819: type regression issue fixed in 4.8.1

* DB PR fixes 1

(cherry picked from commit 693e7ab)

Author: rustagir

source/whats-new.txt

@@ -31,6 +31,12 @@ Learn what's new in:
 What's New in 4.8
 -----------------
 
+.. important:: Upgrade from v4.8.0 to v4.8.1
+
+   Version 4.8.1 fixes a type regression issue introduced in v4.8.0. By
+   upgrading to v4.8.1, you can specify ``_id`` values and sub-documents
+   when performing updates with the ``$set`` or ``$setOnInsert`` operators.
+
 New features of the 4.8 {+driver-short+} release include:
 
 - Added auto-completion and type safety for nested keys in an update filter