[BUG] install.sh does not allow user to specify which release

[MikeSpreitzer]

What did you do

https://github.com/kubestellar/kubestellar/actions/workflows/test-demo-env-creation-script.yml started failing last week, when release 5.9.0 of k3d appeared.

kubestellar's test/e2e/ci/test-demo-env.sh k3d works on my laptop, where I still have release 5.8.3 of k3d installed.

I see that release 5.9.0 picks up vulnerability fixes, which is good. It also seems to have made some functional changes that matter to kubestellar.

I see that k3d's install.sh does not offer any control over which release of k3d gets installed.

What did you expect to happen

I expect to be able to control which version of each dependency gets used.

Using the dynamically determined latest version of a dependency is a logic time bomb and a supply chain vulnerability.

Screenshots or terminal output

Which OS & Architecture

Ubuntu 24.04.4
amd64

Which version of k3d

5.9.0

Which version of docker

See https://github.com/actions/runner-images/blob/ubuntu24/20260525.161/images/ubuntu/Ubuntu2404-Readme.md

[MikeSpreitzer]

Oh, now I see the README says that I can set TAG. Maybe that should be at the top of install.sh too.