Changelog and readme.txt edits.

Committed via a GitHub action: https://github.com/Automattic/jetpack/actions/runs/19246547653

Upstream-Ref: Automattic/jetpack@c4f3f4e

Author: grzegorz-cp

composer.json

@@ -9,7 +9,7 @@
 	},
 	"require-dev": {
 		"yoast/phpunit-polyfills": "^4.0.0",
-		"automattic/jetpack-changelogger": "^6.0.8-alpha",
+		"automattic/jetpack-changelogger": "^6.0.8",
 		"automattic/phpunit-select-config": "^1.0.3"
 	},
 	"suggest": {