fix(gcp): bootstrap

[OliverTrautvetter]

Etcd Disk Management and Persistence

• Added a new method EnsureEtcdDisksMounted to automatically format, mount, and persistently register a dedicated disk (/dev/sdb) for etcd data on each control plane node, ensuring etcd data lands on a dedicated persistent disk. This is run before k0s installation and is idempotent.
• Updated the VM definitions for k0s-1, k0s-2, and k0s-3 to provision a 100GB disk for etcd, ensuring each control plane node has the necessary storage.
• Integrated the etcd disk mounting step into the main bootstrap process, so that etcd storage is set up before any further installation steps.

Configuration and Idempotency Improvements

• Changed the creation of the cloud-config ConfigMap to use kubectl --dry-run=client -o yaml | kubectl apply -f -, making the operation idempotent and preventing errors if the ConfigMap already exists.
• Improved the script that enables the cloud provider integration for k0s systemd services by making the sed operation idempotent and only adding the flag if it's not already present. Also, added a connection timeout and made the SSH command tolerant to errors.

Minor Script Fixes

• Corrected the way cc-deployment.yaml is written to avoid duplicate content.