Backport jetpack 14.0-beta Changes (#40024)

* Changelog and readme.txt edits.

* Amend readme.txt

Committed via a GitHub action: https://github.com/Automattic/jetpack/actions/runs/11667212003

Upstream-Ref: Automattic/jetpack@a7dc7da

Author: tbradsha

composer.json

@@ -9,7 +9,7 @@
 	},
 	"require-dev": {
 		"yoast/phpunit-polyfills": "^1.1.1",
-		"automattic/jetpack-changelogger": "^4.2.8-alpha",
+		"automattic/jetpack-changelogger": "^4.2.8",
 		"automattic/wordbless": "dev-master"
 	},
 	"suggest": {