Update dependency wp-coding-standards/wpcs to v3

Author: renovate[bot]

app/wp-content/themes/md-starter/composer.json

@@ -5,7 +5,7 @@
     },
     "require-dev": {
         "squizlabs/php_codesniffer": "3.7.2",
-        "wp-coding-standards/wpcs": "2.3.0"
+        "wp-coding-standards/wpcs": "3.0.0"
     },
     "scripts": {
         "config-set": "vendor/bin/phpcs --config-set installed_paths wpcs",