Release v0.12.0

Author: jonatanklosko

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
-## [Unreleased](https://github.com/livebook-dev/livebook/tree/main)
+## [v0.12.0](https://github.com/livebook-dev/livebook/tree/v0.12.0) (2023-12-22)
 
 ### Added
 

mix.exs

@@ -6,7 +6,7 @@ defmodule Livebook.MixProject do
   use Mix.Project
 
   @elixir_requirement "~> 1.15.2 or ~> 1.16-dev"
-  @version "0.12.0-dev"
+  @version "0.12.0"
   @description "Automate code & data workflows with interactive notebooks"
 
   def project do