Fixes #856 - Add CentOS/RHEL 10 as supported distro and add a note about Valkey

Co-authored-by: Florian Liebe <fl@zammad.com>

Author: ralf401

prerequisites/software.rst

@@ -73,7 +73,7 @@ Below you can find all distributions Zammad provides packages for.
    :header: "Distribution", "Versions"
    :widths: 20, 20
 
-   "CentOS / RHEL", "9"
+   "CentOS / RHEL", "9, 10"
    "Debian", "11, 12 & 13"
    "OpenSUSE / SLES", "Leap 15.x / 15"
    "Ubuntu", "22.04 & 24.04"
@@ -188,6 +188,10 @@ a secure way.
 Available environment variables for standard and Sentinel setups are briefly
 mentioned in the :doc:`Redis Variables </appendix/redis>` page.
 
+.. note:: CentOS and RHEL 10 use `Valkey <https://valkey.io/>`_ as a
+   drop-in-replacement for Redis. During the Zammad installation on those
+   distros, it gets installed automatically as a dependency.
+
 .. _prerequisites_elasticsearch:
 
 2.6 Elasticsearch (optional)