Update Composer deps

Author: wpscholar

composer.json

@@ -15,8 +15,9 @@
   },
   "require-dev": {
     "phpunit/phpunit": "^9.6.0",
-    "wpscholar/phpcs-standards-wpscholar": "^1.0",
     "wp-cli/wp-cli-bundle": "^2.11",
+    "wp-phpunit/wp-phpunit": "^6.8",
+    "wpscholar/phpcs-standards-wpscholar": "^1.0",
     "yoast/phpunit-polyfills": "^4.0"
   },
   "scripts": {