feat: drop tests for kubernetes v1.28 (#810)

Kubernetes v1.28 is End of Life since 2024-10-22. In accordance with our Versioning policy.

Author: lukasmetzner

.github/workflows/test_e2e.yml

@@ -19,7 +19,6 @@ jobs:
       fail-fast: false # Continue tests matrix if a flaky run occurs.
       matrix:
         k3s:
-          - v1.28
           - v1.29
           - v1.30
           - v1.31

README.md

@@ -184,7 +184,7 @@ Current Kubernetes Releases: https://kubernetes.io/releases/
 | 1.31       |                   latest |  https://github.com/hetznercloud/hcloud-cloud-controller-manager/releases/latest/download/ccm-networks.yaml |
 | 1.30       |                   latest |  https://github.com/hetznercloud/hcloud-cloud-controller-manager/releases/latest/download/ccm-networks.yaml |
 | 1.29       |                   latest |  https://github.com/hetznercloud/hcloud-cloud-controller-manager/releases/latest/download/ccm-networks.yaml |
-| 1.28       |                   latest |  https://github.com/hetznercloud/hcloud-cloud-controller-manager/releases/latest/download/ccm-networks.yaml |
+| 1.28       |                  v1.20.0 | https://github.com/hetznercloud/hcloud-cloud-controller-manager/releases/download/v1.20.0/ccm-networks.yaml |
 | 1.27       |                  v1.20.0 | https://github.com/hetznercloud/hcloud-cloud-controller-manager/releases/download/v1.20.0/ccm-networks.yaml |
 | 1.26       |                  v1.19.0 | https://github.com/hetznercloud/hcloud-cloud-controller-manager/releases/download/v1.19.0/ccm-networks.yaml |
 | 1.25       |                  v1.19.0 | https://github.com/hetznercloud/hcloud-cloud-controller-manager/releases/download/v1.19.0/ccm-networks.yaml |
@@ -198,7 +198,7 @@ Current Kubernetes Releases: https://kubernetes.io/releases/
 | 1.31       |                   latest |  https://github.com/hetznercloud/hcloud-cloud-controller-manager/releases/latest/download/ccm.yaml |
 | 1.30       |                   latest |  https://github.com/hetznercloud/hcloud-cloud-controller-manager/releases/latest/download/ccm.yaml |
 | 1.29       |                   latest |  https://github.com/hetznercloud/hcloud-cloud-controller-manager/releases/latest/download/ccm.yaml |
-| 1.28       |                   latest |  https://github.com/hetznercloud/hcloud-cloud-controller-manager/releases/latest/download/ccm.yaml |
+| 1.28       |                  v1.20.0 | https://github.com/hetznercloud/hcloud-cloud-controller-manager/releases/download/v1.20.0/ccm.yaml |
 | 1.27       |                  v1.20.0 | https://github.com/hetznercloud/hcloud-cloud-controller-manager/releases/download/v1.20.0/ccm.yaml |
 | 1.26       |                  v1.19.0 | https://github.com/hetznercloud/hcloud-cloud-controller-manager/releases/download/v1.19.0/ccm.yaml |
 | 1.25       |                  v1.19.0 | https://github.com/hetznercloud/hcloud-cloud-controller-manager/releases/download/v1.19.0/ccm.yaml |