Update roots/wordpress requirement from ^6.5 to ^6.6

Updates the requirements on [roots/wordpress](https://github.com/roots/wordpress) to permit the latest version.
- [Release notes](https://github.com/roots/wordpress/releases)
- [Commits](roots/wordpress@6.5...6.6)

---
updated-dependencies:
- dependency-name: roots/wordpress
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

composer.json

@@ -36,7 +36,7 @@
 		"phpcompatibility/php-compatibility": "^9.3",
 		"phpunit/phpunit": "^6.5 || ^7.5 || ^7.5 || ^9.6 || ^10.5 || ^11",
 		"rector/rector": "0.17.10",
-		"roots/wordpress": "^6.5",
+		"roots/wordpress": "^6.6",
 		"syntatis/coding-standard": "^1.2",
 		"wp-phpunit/wp-phpunit": "^6.5",
 		"yoast/phpunit-polyfills": "^2.0"