Fix super-linter v8.3.1 composer install errors

Disable PHP_BUILTIN and PHP_PHPCS validators to prevent
super-linter from attempting composer install on vendor files.
The PHP extensions (ext-pdo, ext-xml) are not available in the
super-linter container, causing the build to fail.

Author: jdecool

.github/workflows/ci.yml

@@ -69,6 +69,8 @@ jobs:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           VALIDATE_CHECKOV: false
           VALIDATE_JSCPD: false
-          VALIDATE_PHP_PSALM: false
+          VALIDATE_PHP_BUILTIN: false
+          VALIDATE_PHP_PHPCS: false
           VALIDATE_PHP_PHPSTAN: false # temporary disabled until superlinter supports phpstan 2
+          VALIDATE_PHP_PSALM: false
           VALIDATE_YAML_PRETTIER: false