Correct menu option for almalinux on arm64

Fixes https://github.com/netbootxyz/netboot.xyz/issues/1155

roles/netbootxyz/templates/menu/linux-arm.ipxe.j2

@@ -5,7 +5,7 @@ goto ${menu} ||
 :linux_menu
 menu Linux Installers - Current Arch [ ${arch} ]
 item --gap Popular Linux Operating Systems:
-item alpinelinux ${space} AlmaLinux
+item almalinux ${space} AlmaLinux
 item alpinelinux ${space} Alpine Linux
 item centos ${space} CentOS
 item debian ${space} Debian