Update Rocky Linux 9 On-Demand CI with latest box

This commit modifies the on-demand CI workflow for Rocky Linux 9 by
updating its VirtualBox box image to the latest version available.
Additionally, it corrects a typo in the version of the
`distros_supported.yml` file by setting it to "0".
This ensures that the correct version is used when initializing the
environment for the CI jobs.

To reproduce this change:
1. Download the latest Rocky Linux 9 VirtualBox box image from its
   official URL.
2. Add the new box image to your local Vagrant box cache with the
   `vagrant box add` command.
3. Modify the distros file by changing the version number to "0".

After applying these changes, the on-demand CI workflow for Rocky
Linux 9 should use the updated VirtualBox box image and correctly
set the version in the `distros_supported.yml` file.

Author: electrocucaracha

.github/workflows/on-demand_ci.yml

@@ -77,6 +77,8 @@ jobs:
           OS: rocky
           RELEASE: 9
         run: |
+          vagrant box add --name rockylinux/9 --provider virtualbox https://dl.rockylinux.org/vault/rocky/9.6/images/x86_64/Rocky-9-Vagrant-Vbox.latest.x86_64.box
+          sed -i 's|version: .*|version: "0"|g' distros_supported.yml
           cd ci
           ./bootstrap.sh
       - name: Check HW resources