doc: relnotes: Remove draft status from 2.3 release notes

Mark the release notes as complete.

Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
diff --git a/doc/releases/release-notes-2.3.rst b/doc/releases/release-notes-2.3.rst
index 8e14731..5d6d031 100644
--- a/doc/releases/release-notes-2.3.rst
+++ b/doc/releases/release-notes-2.3.rst
@@ -2,8 +2,8 @@
 
 .. _zephyr_2.3:
 
-Zephyr 2.3.0 (Working Draft)
-############################
+Zephyr 2.3.0
+############
 
 We are pleased to announce the release of Zephyr RTOS version 2.3.0.