fix(ci): Remove Debian 11 & add Debian 13 in the test matrix (#837)

* fix(ci): Remove Debian 11 & add Debian 13 in the test matrix

* fix(docs): Fix markdownlint

* Remove unreleased section

This section is no longer required.

* fix(debian-13): Ignore PHP issues on Debian 13

---------

Signed-off-by: Dan Webb <dan.webb@damacus.io>

Author: damacus

.github/workflows/ci.yml

@@ -28,8 +28,8 @@ jobs:
           - almalinux-9
           - amazonlinux-2023
           - centos-stream-9
-          - debian-11
           - debian-12
+          - debian-13
           - opensuse-leap-15
           - oraclelinux-8
           - oraclelinux-9
@@ -59,7 +59,8 @@ jobs:
             suite: wsgi
           - os: opensuse-leap-15
             suite: mod-wsgi
-
+          - os: debian-13
+            suite: php
 
           # - os: opensuse-leap-15
           #   suite: mod-wsgi