DOCS-14631 finalize release 4.2.15 changelog

Author: andf-mongodb

source/includes/changelogs/releases/4.2.15.rst

@@ -33,6 +33,7 @@ Replication
 - :issue:`SERVER-44316` Log message in InitialSyncer for setting begin applying timestamp is incorrect
 - :issue:`SERVER-45919` replSetReconfig should be allowed to fail with InterruptedDueToReplStateChange when racing with an election
 - :issue:`SERVER-53447` Blacklist insert1.js with from transaction passthrough tests with failures
+- :issue:`SERVER-55465` Fix Invariant upon failed request for a vote from the current primary in the election dry-run of catchup takeover
 - :issue:`SERVER-55766` Introduce an optimized "for restore" startup replication recovery mechanism
 - :issue:`SERVER-56054` Change minThreads value for replication writer thread pool to 0
 - :issue:`SERVER-56415` AwaitNodesAgreeOnPrimary doesn't work when given non-default set of nodes

source/release-notes/4.2.txt

@@ -15,8 +15,8 @@ Minor Releases
 
 .. _4.2.15-release-notes:
 
-4.2.15 - Upcoming
-~~~~~~~~~~~~~~~~~
+4.2.15 - Jul 13, 2021
+~~~~~~~~~~~~~~~~~~~~~
 
 Issues fixed in 4.2.15: