mailparse doesn't support PHP 8.4 anymore (#980)

Error: implicit declaration of function 'php_strtolower'

From https://github.com/php/php-src/blob/php-8.4.0RC1/UPGRADING.INTERNALS:
  The php_strtoupper(), php_string_toupper(), php_strtolower(), and
  php_string_tolower() functions has been removed, use zend_str_toupper(),
  zend_string_toupper(), zend_str_tolower(), and zend_string_tolower()
  respectively instead.

data/supported-extensions

@@ -48,7 +48,7 @@ ldap 5.5 5.6 7.0 7.1 7.2 7.3 7.4 8.0 8.1 8.2 8.3 8.4
 luasandbox 5.5 5.6 7.0 7.1 7.2 7.3 7.4 8.0 8.1 8.2 8.3 8.4
 lz4 5.6 7.0 7.1 7.2 7.3 7.4 8.0 8.1 8.2 8.3 8.4
 lzf 5.5 5.6 7.0 7.1 7.2 7.3 7.4 8.0 8.1 8.2 8.3 8.4
-mailparse 5.5 5.6 7.0 7.1 7.2 7.3 7.4 8.0 8.1 8.2 8.3 8.4
+mailparse 5.5 5.6 7.0 7.1 7.2 7.3 7.4 8.0 8.1 8.2 8.3
 maxminddb 7.2 7.3 7.4 8.0 8.1 8.2 8.3 8.4
 mcrypt 5.5 5.6 7.0 7.1 7.2 7.3 7.4 8.0 8.1 8.2 8.3
 memcache 5.5 5.6 7.0 7.1 7.2 7.3 7.4 8.0 8.1 8.2 8.3 8.4