Stop duplicating the supported PHP version (link to the support page instead).

PiperOrigin-RevId: 674070935

php/README.md

@@ -14,13 +14,8 @@ generation functionality.
 
 ## Requirements
 
-Using the PHP runtime library requires:
+For information on supported language versions and how the support levels for
-
+PHP versions will change over time, see
--   C extension: PHP 7.x, 8.x
--   [PHP package](http://php.net/downloads.php): PHP 7.4+
-
-For information on how the support levels for PHP versions will change over
-time, see
 [Supported PHP versions](https://cloud.google.com/php/getting-started/supported-php-versions).
 
 ## Installation