Documentation: Remove PHP 5.6 from allowed PHP versions in dependencies guide

documentation/dependencies.html

@@ -71,7 +71,7 @@ We recommend using HTML5-compatible technology.
 <h2>Dependencies - server-side</h2>
 <ul>
   <li>Apache 2+</li>
-  <li>PHP 5.6 (not recommended) with MySQL bindings or PHP 7.2 (recommended) or 7.3. PHP 7.0 is not supported by this version of Chamilo. PHP 7.1 should be supported but we lack elements of infrastructure to check it fully and thoroughly.</li>
+  <li>PHP 7.2, 7.3 or 7.4 (recommended). PHP 5.6 and 7.0 are not supported by this version of Chamilo. PHP 7.1 should be supported but we lack elements of infrastructure to check it fully and thoroughly.</li>
   <li>MySQL 5.6+ or any version of MariaDB database server</li>
   <li>php-curl</li>
   <li>php-dom (usually available by default)</li>