Bump version to 3.4-stable \o/

After the decision to continue feature development for the `3.x` branch
alongside the `master` branch for Godot 4.0, we released 3.3-stable in
April 2021.

6 months and 2000 commits later, Godot 3.4 is another feature-packed milestone
for Godot 3, with a ton of improvements and fixes to make it a great option
for use in production while we wait for Godot 4.0!

A big thankyou to all contributors who work tirelessly on our two parallel
development branches and made this stable 3.4 release possible.

CHANGELOG.md

@@ -4,7 +4,9 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
-## [3.4] - TBD
+## [3.4] - 2021-11-05
+
+See the [release announcement](https://godotengine.org/article/godot-3-4-is-released) for details.
 
 ### Added
 
@@ -114,6 +116,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 #### Localization
 
 - Add support for translating the class reference ([GH-53511](https://github.com/godotengine/godot/pull/53511)).
+  * Includes Chinese (Simplified) and Spanish translations with high completion ratio, and initial translations for French, Japanese, and German.
 - Allow overriding `get_message` with virtual method ([GH-53207](https://github.com/godotengine/godot/pull/53207)).
 
 #### Mono (C#)

version.py

@@ -3,7 +3,7 @@
 major = 3
 minor = 4
 patch = 0
-status = "rc"
+status = "stable"
 module_config = ""
 year = 2021
 website = "https://godotengine.org"