Update symfony packages to v6 (major) (#25158)

* Update symfony packages to v6
* Make it work
* Have php:lint when run with php5.6 skip /php7/ dirs

Co-authored-by: Renovate Bot <bot@renovateapp.com>
Co-authored-by: Brad Jorsch <brad.jorsch@automattic.com>

Committed via a GitHub action: https://github.com/Automattic/jetpack/actions/runs/2719513045

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).
 
+## [2.11.7-alpha] - unreleased
+
+This is an alpha version! The changes listed here are not final.
+
+### Changed
+- Updated package dependencies.
+
 ## [2.11.6] - 2022-06-21
 ### Changed
 - Renaming `master` to `trunk`.
@@ -257,6 +264,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Add Custom Autoloader
 
+[2.11.7-alpha]: https://github.com/Automattic/jetpack-autoloader/compare/v2.11.6...v2.11.7-alpha
 [2.11.6]: https://github.com/Automattic/jetpack-autoloader/compare/v2.11.5...v2.11.6
 [2.11.5]: https://github.com/Automattic/jetpack-autoloader/compare/v2.11.4...v2.11.5
 [2.11.4]: https://github.com/Automattic/jetpack-autoloader/compare/v2.11.3...v2.11.4

composer.json

@@ -8,7 +8,7 @@
 	},
 	"require-dev": {
 		"yoast/phpunit-polyfills": "1.0.3",
-		"automattic/jetpack-changelogger": "^3.1"
+		"automattic/jetpack-changelogger": "^3.2"
 	},
 	"autoload": {
 		"classmap": [