Update php-extensions.md - Add redis php module

Author: ananth-iyer

help/_includes/templated/php-extensions.md

@@ -29,6 +29,7 @@ Adobe Commerce requires:
 -  `ext-zip`
 -  `ext-zlib`
 -  `lib-libxml`
+-  `lib-redis`
 
 Magento Open Source requires:
 
@@ -58,3 +59,4 @@ Magento Open Source requires:
 -  `ext-zip`
 -  `ext-zlib`
 -  `lib-libxml`
+-  `lib-redis`