Add warn.deprecated.feature-8-4-0 to language-snippets.ent

Author: TimWolla

language-snippets.ent

@@ -363,6 +363,11 @@ xmlns="http://docbook.org/ns/docbook"><simpara>This function has been
 <emphasis>DEPRECATED</emphasis> as of PHP 8.3.0. Relying on this function
 is highly discouraged.</simpara></warning>'>
 
+<!ENTITY warn.deprecated.feature-8-4-0 '<warning
+xmlns="http://docbook.org/ns/docbook"><simpara>This feature has been
+<emphasis>DEPRECATED</emphasis> as of PHP 8.4.0. Relying on this feature
+is highly discouraged.</simpara></warning>'>
+
 <!ENTITY warn.deprecated.function-8-4-0 '<warning
 xmlns="http://docbook.org/ns/docbook"><simpara>This function has been
 <emphasis>DEPRECATED</emphasis> as of PHP 8.4.0. Relying on this function