ansible: create playbook to clean dnsmasq dhcp leases

[herzogf]

homek8s should provide ansible scripts to clear the dnsmasq dhcp leases completely or for individual nodes only (e.g. needed in local test environment when we don't want to provision the gateway all the time but re-use a running raspberry pi VM).

To clean all leases:

sudo systemctl stop dnsmasq
sudo rm -f /var/lib/misc/dnsmasq.leases
sudo systemctl start dnsmasq

For individual leases there's a package dnsmasq-utils which should do the trick:

• https://packages.debian.org/buster/dnsmasq-utils
• https://manpages.debian.org/jessie/dnsmasq-utils/dhcp_release.1.en.html