ci(.github): update helm-chart-smoketest with more k8s variations

[vdice]

Describe your changes

• Updates the helm install smoke test with more k8s flavors! Here we add minikube, microk8s and k3d
• Since they run in parallel, I figured running all cases both on PRs and merges to main is fine for now -- thoughts?

These distros all had GH actions ready-to-use. For other distros we'd like to cover under test (k0s, etc), we could either craft a reusable action in-house and stick to the same matrix-based approach added here... or maybe break out into separate workflows.

• [ ] Depends on https://github.com/spinkube/runtime-class-manager/pull/264 (microk8s specifically)
  • (See successful runs on fork which incorporates PR#264 alongside this commit)

Issue ticket number and link

Ref https://github.com/spinkube/runtime-class-manager/issues/48

Checklist before requesting a review

• [x] I have performed a self-review of my code
• [ ] If it is a core feature, I have added thorough tests.
• I tested the changes with the following distributions:
  • [x] Kind
  • [x] MiniKube
  • [x] MicroK8s
  • [x] K3s
  • [ ] Rancher RKE2
  • [ ] Azure AKS
  • [ ] GCP GKE (Ubuntu nodes)
  • [ ] AWS EKS (AmazonLinux2 nodes)
  • [ ] AWS EKS (Ubuntu nodes)
  • [ ] Digital Ocean Kubernetes