chore(deps): update dependency phpunit/phpunit to v9.6.33 [security]

Author: renovate[bot]

composer.json

@@ -11,7 +11,7 @@
   "require-dev": {
     "dealerdirect/phpcodesniffer-composer-installer": "0.7.0",
     "phpcompatibility/phpcompatibility-wp": "2.1.0",
-    "phpunit/phpunit": "9.1.4",
+    "phpunit/phpunit": "9.6.33",
     "squizlabs/php_codesniffer": "3.5.5",
     "wp-coding-standards/wpcs": "2.3.0",
     "slevomat/coding-standard": "6.3.9",