Revert VPN integration on 1.24

[manuelbuil]

Environmental Info:
K3s Version:

Node(s) CPU architecture, OS, and Version:

Cluster Configuration:

Describe the bug:

VPN integration will never work on 1.24. The reason is that we need latest flannel but latest flannel requires 1.25 kube-api. Therefore, we should revert it

Steps To Reproduce:

• Installed K3s:

Expected behavior:

Actual behavior:

Additional context / logs:

[rancher-max]

This was reverted pretty quickly before any validations were done, so I think is okay to close as any regressions potentially caused by the merge + revert should be caught during standard testing.