doc: release: Finalize v4.2.0 release notes and migration guide

Remove working draft status from the v4.2.0 release notes and migration
guide.

Signed-off-by: Dan Kalowsky <[email protected]>
Signed-off-by: Daniel DeGrasse <[email protected]>

Author: danieldegrasse

doc/releases/migration-guide-4.2.rst

@@ -7,8 +7,8 @@
 
 .. _migration_4.2:
 
-Migration guide to Zephyr v4.2.0 (Working Draft)
-################################################
+Migration guide to Zephyr v4.2.0
+################################
 
 This document describes the changes required when migrating your application from Zephyr v4.1.0 to
 Zephyr v4.2.0.

doc/releases/release-notes-4.2.rst

@@ -26,8 +26,8 @@
 
 .. _zephyr_4.2:
 
-Zephyr 4.2.0 (Working Draft)
-############################
+Zephyr 4.2.0
+############
 
 We are pleased to announce the release of Zephyr version 4.2.0.