Unmount Cloundinit iso after machine are provisioned

[mcbenjemaa]

Describe the solution you'd like
[A clear and concise description of what you want to happen.]

The machines are started and the cloudinit stays mounted.
and the tag, is still there go-proxmox+cloud-init

Anything else you would like to add:
[Miscellaneous information that will assist in solving the issue.]

unmount the cd rom, and remove the tag.

Environment:

• Cluster-api-provider-proxmox version:
• Kubernetes version: (use kubectl version):
• OS (e.g. from /etc/os-release):

[mcbenjemaa]

Started luthermonson/go-proxmox#131

[mcbenjemaa]

implemented #154