(maint) add supported docker el9 platforms to matrix

Author: h0tw1r3

exe/matrix_from_metadata_v2

@@ -43,14 +43,18 @@ ARM_IMAGE_TABLE = {
 DOCKER_PLATFORMS = {
   'CentOS-7' => 'litmusimage/centos:7',
   'CentOS-8' => 'litmusimage/centos:stream8', # Support officaly moved to Stream8, metadata is being left as is
+  'CentOS-9' => 'litmusimage/centos:stream9',
   'Rocky-8' => 'litmusimage/rockylinux:8',
+  'Rocky-9' => 'litmusimage/rockylinux:9',
   'AlmaLinux-8' => 'litmusimage/almalinux:8',
+  'AlmaLinux-9' => 'litmusimage/almalinux:9',
   'Debian-9' => 'litmusimage/debian:9',
   'Debian-10' => 'litmusimage/debian:10',
   'Debian-11' => 'litmusimage/debian:11',
   'Debian-12' => 'litmusimage/debian:12',
   'OracleLinux-7' => 'litmusimage/oraclelinux:7',
   'OracleLinux-8' => 'litmusimage/oraclelinux:8',
+  'OracleLinux-9' => 'litmusimage/oraclelinux:9',
   'Scientific-7' => 'litmusimage/scientificlinux:7',
   'Ubuntu-18.04' => 'litmusimage/ubuntu:18.04',
   'Ubuntu-20.04' => 'litmusimage/ubuntu:20.04',