Vagrant file needs playbook path updated

[Zie0]

Since https://github.com/k3s-io/k3s-ansible/commit/5a12415b3c2bb1a0543c2f48d173c62a9fdd4d52 commit the vagrant file's provision function needs ansible.playbook = "playbook/site.yml" changed to ... "playbooks/site.yaml"

Without this change the vagrant up fails because it cannot find the site.yml playbook

The vagrant up failure was resolved by making that change

==> server-0: An error occurred. The error will be shown after all tasks complete.
An error occurred while executing multiple actions in parallel.
Any errors that occurred are shown below.

An error occurred while executing the action on the 'server-0'
machine. Please handle this error then try again:

`playbook` does not exist on the host: k3s-ansible/playbook/site.yml

An error occurred while executing the action on the 'server-1'
machine. Please handle this error then try again:

`playbook` does not exist on the host: k3s-ansible/playbook/site.yml

An error occurred while executing the action on the 'server-2'
machine. Please handle this error then try again:

`playbook` does not exist on the host: k3s-ansible/playbook/site.yml

An error occurred while executing the action on the 'agent-0'
machine. Please handle this error then try again:

`playbook` does not exist on the host: k3s-ansible/playbook/site.yml

An error occurred while executing the action on the 'agent-1'
machine. Please handle this error then try again:

`playbook` does not exist on the host: k3s-ansible/playbook/site.yml