[Bug] XssTemplateSniff does not detect some use cases

[lenaorobei]

Preconditions

Create fixture with following code:

<?= /* @noEscape */ json_encode($config) ?>

Steps to reproduce

Run Magento2 Coding Standard against this code.

Expected result

No issues detected.
/* @noEscape */ is allowed.
https://devdocs.magento.com/guides/v2.3/frontend-dev-guide/templates/template-security.html

Actual result

WARNING | Unescaped output detected.