Update dependency slevomat/coding-standard to v8.20.0

Author: renovate[bot]

composer.json

@@ -52,7 +52,7 @@
         "phpstan/phpstan-deprecation-rules": "2.0.3",
         "phpstan/phpstan-strict-rules": "2.0.4",
         "psalm/plugin-laravel": "3.0.4",
-        "slevomat/coding-standard": "8.18.1",
+        "slevomat/coding-standard": "8.20.0",
         "spatie/laravel-ignition": "2.9.1",
         "spatie/ray": "1.42.0",
         "squizlabs/php_codesniffer": "3.13.2",