laminas/laminas-captcha 2.1.6

Based on https://github.com/zendframework/zend-captcha/releases/tag/release-2.1.6 (commit a7e25ed67d9a72677e27988a118e4616feb41ac6 in this repo)

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- **ZF2014-01:** Potential XXE/XEE attacks using PHP functions:
  `simplexml_load_*`, `DOMDocument::loadXML`, and `xml_parse`. A new component,
  `laminas-xml`, was introduced to mitigate XML eXternal Entity and XML Entity
  Expansion vectors that are present in older versions of libxml2 and/or PHP.
  `Laminas\Json\Json::fromXml()` and `Laminas\XmlRpc`'s `Response` and `Fault` classes
  were potentially vulnerable to these attacks. If you use either of these
  components, we recommend upgrading immediately.