Composer/ruleset: allow for PHP 8.1 token constants

PHP 8.1 will introduce yet more new token constants. Detection for `T_READONLY` is already in PHPCompatibility 10.0, `T_ENUM` will follow shortly.

As PHPCS polyfills these tokens, we should allow for these to be used in external PHPCS standards.

The token constants are expected to be backfilled by PHPCS as of version 3.7.0.

Author: jrfnl

PHPCSDev/ruleset.xml

@@ -29,6 +29,8 @@
         <exclude name="PHPCompatibility.Constants.NewConstants.t_name_fully_qualifiedFound"/>
         <exclude name="PHPCompatibility.Constants.NewConstants.t_name_qualifiedFound"/>
         <exclude name="PHPCompatibility.Constants.NewConstants.t_name_relativeFound"/>
+        <exclude name="PHPCompatibility.Constants.NewConstants.t_readonlyFound"/>
+        <exclude name="PHPCompatibility.Constants.NewConstants.t_enumFound"/>
         <exclude name="PHPCompatibility.Constants.RemovedConstants.t_bad_characterFound"/>
     </rule>