Update "Install a Kubernetes cluster on cloud servers" tutorial

[cbeneke]

This PR updates the "Install a Kubernetes cluster on cloud servers" tutorial with a verified installation using the latest Stable Ubuntu version (26.04) and Kubernetes version. All HCloud dependencies were set up and tested successfully in accordance to the document.

An additional section on the unofficial hcloud-fip-controller as alternative to a more expensive Hetzner LoadBalancer was introduced.

[svenja11]

Thank you for the update @cbeneke!

Please add the following comment in this PR and I will merge it (remember to replace YOUR NAME <YOUR@EMAILPROVIDER.TLD> with your own information:

I have read and understood the Contributor's Certificate of Origin available at the end of
https://raw.githubusercontent.com/hetzneronline/community-content/master/tutorial-template.md
and I hereby certify that I meet the contribution criteria described in it.
Signed-off-by: YOUR NAME YOUR@EMAILPROVIDER.TLD

[cbeneke]

I have read and understood the Contributor's Certificate of Origin available at the end of
https://raw.githubusercontent.com/hetzneronline/community-content/master/tutorial-template.md
and I hereby certify that I meet the contribution criteria described in it.
Signed-off-by: Christian Beneke c.beneke@wirelab.org