DOCS-16252 Finalize 6.0.8 Changelog (#3913) (#4026)

* DOCS-16252 Finalize 6.0.8 Changelog

* correct date

Author: ajhuh-mdb

source/release-notes/6.0.txt

@@ -45,8 +45,8 @@ Patch Releases
 
 .. _6.0.8-release-notes:
 
-6.0.8 - Upcoming
-~~~~~~~~~~~~~~~~
+6.0.8 - Jul 13, 2023
+~~~~~~~~~~~~~~~~~~~~
 
 - :issue:`SERVER-61127` Multi-writes may exhaust the number of retry attempts 
   in the presence of ongoing chunk migrations