Add almalinux 9 to the checks

README.md

@@ -37,6 +37,7 @@ First thing you need is a VM (or even a physical machine if you wish) where to i
 Supported Linux distributions and versions:
 
 - CentOS 8 Stream
+- AlmaLinux 9
 - AlmaLinux 8
 - Rocky Linux 8
 - Debian 11

xo-install.sh

@@ -1266,8 +1266,8 @@ function CheckOS {
     fi
 
     # for future if/when something above 8 is released
-    if [[ "$OSNAME" == "AlmaLinux" ]] && [[ "$OSVERSION" != "8" ]]; then
-        printfail "Only AlmaLinux 8 supported"
+    if [[ "$OSNAME" == "AlmaLinux" ]] && [[ "$OSVERSION" =~ ^(8|9)$ ]]; then
+        printfail "Only AlmaLinux 8/9 supported"
         exit 1
     fi