Backport jetpack 16.2-a.3 changes (#51545)

* Changelog and readme.txt edits.

* Sort 16.2-a.3 changelog entries

* Update stable tag in readme.txt

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Co-authored-by: Chris Jean <chris.jean@automattic.com>

Committed via a GitHub action: https://github.com/Automattic/jetpack/actions/runs/32851203157

Upstream-Ref: Automattic/jetpack@4a44540

Author: chrisbliss18

composer.json

@@ -6,10 +6,10 @@
 	"require": {
 		"php": ">=7.2",
 		"automattic/jetpack-assets": "^4.4.11",
-		"automattic/jetpack-connection": "^8.12.0-alpha",
+		"automattic/jetpack-connection": "^8.12.0",
 		"automattic/jetpack-constants": "^3.0.12",
 		"automattic/jetpack-external-connections": "^0.1.39",
-		"automattic/jetpack-status": "^6.5.0-alpha"
+		"automattic/jetpack-status": "^6.5.0"
 	},
 	"require-dev": {
 		"yoast/phpunit-polyfills": "^4.0.0",