Release changelog and update readme for migration plugin

Committed via a GitHub action: https://github.com/Automattic/jetpack/actions/runs/6742449563

CHANGELOG.md

@@ -5,6 +5,13 @@ 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/)
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.12.1-alpha] - unreleased
+
+This is an alpha version! The changes listed here are not final.
+
+### Changed
+- Update dependencies.
+
 ## [0.12.0] - 2023-10-31
 ### Added
 - Add sending Jetpack version to BlazePress Calypso App. [#33823]
@@ -229,6 +236,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 - Updated package dependencies. [#27906]
 
+[0.12.1-alpha]: https://github.com/automattic/jetpack-blaze/compare/v0.12.0...v0.12.1-alpha
 [0.12.0]: https://github.com/automattic/jetpack-blaze/compare/v0.11.0...v0.12.0
 [0.11.0]: https://github.com/automattic/jetpack-blaze/compare/v0.10.4...v0.11.0
 [0.10.4]: https://github.com/automattic/jetpack-blaze/compare/v0.10.3...v0.10.4

composer.json

@@ -4,8 +4,8 @@
 	"type": "jetpack-library",
 	"license": "GPL-2.0-or-later",
 	"require": {
-		"automattic/jetpack-assets": "^1.18.14-alpha",
-		"automattic/jetpack-connection": "^1.58.3-alpha",
+		"automattic/jetpack-assets": "^1.18.14",
+		"automattic/jetpack-connection": "^1.58.3",
 		"automattic/jetpack-constants": "^1.6.23",
 		"automattic/jetpack-plans": "^0.3.5",
 		"automattic/jetpack-redirect": "^1.7.27",

package.json

@@ -23,8 +23,8 @@
 	},
 	"dependencies": {
 		"@automattic/jetpack-analytics": "^0.1.27",
-		"@automattic/jetpack-components": "^0.44.4-alpha",
-		"@automattic/jetpack-shared-extension-utils": "^0.12.4",
+		"@automattic/jetpack-components": "^0.44.4",
+		"@automattic/jetpack-shared-extension-utils": "^0.12.5",
 		"@wordpress/block-editor": "12.12.0",
 		"@wordpress/components": "25.10.0",
 		"@wordpress/compose": "6.21.0",