doc: release-notes: Remove "Working Draft" status

This commit removes the "Working Draft" status from the Zephyr 3.3.0
release notes.

Signed-off-by: Stephanos Ioannidis <[email protected]>

Author: stephanosio

doc/releases/release-notes-3.3.rst

@@ -2,8 +2,8 @@
 
 .. _zephyr_3.3:
 
-Zephyr 3.3.0 (Working Draft)
-############################
+Zephyr 3.3.0
+############
 
 We are pleased to announce the release of Zephyr version 3.3.0.