chore(deps): update dependency phpcompatibility/phpcompatibility-wp to v2.1.5

Author: renovate[bot]

composer.json

@@ -10,7 +10,7 @@
   },
   "require-dev": {
     "dealerdirect/phpcodesniffer-composer-installer": "0.7.0",
-    "phpcompatibility/phpcompatibility-wp": "2.1.0",
+    "phpcompatibility/phpcompatibility-wp": "2.1.5",
     "phpunit/phpunit": "9.1.4",
     "squizlabs/php_codesniffer": "3.5.5",
     "wp-coding-standards/wpcs": "2.3.0",