Drop support for k3s 1.19 or lower, bump calico to 3.21 for k3s 1.20, and calico 3.23 for k3s 1.21+

[consideRatio]

No description provided.

[manics]

From https://projectcalico.docs.tigera.io/getting-started/kubernetes/requirements

Kubernetes requirements
Supported versions

We test Calico v3.23 against the following Kubernetes versions.

v1.21
v1.22
v1.23

Due to changes in the Kubernetes API, Calico v3.23 will not work on Kubernetes v1.15 or below. v1.16-v1.18 may work, but they are no longer tested.

[consideRatio]

@manics what do you think about going for a v3 release, and bumping to supporting only k8s 1.20+ from now on? I'm thinking those that want to stay behind if they need to test against k8s 1.19 or lower can do so, and those that have test suites that don't fail when bumping to v3 can go for that.

[manics]

Sounds good to me! If it's a major bump it's probably worth reviewing all components and bumping them if they're EOL

[consideRatio]

@manics I'm pushing this onward to a v3 release now.

• I had to use an older version for calico in k3s 1.20 because a poddisruptionbudget resource was declared with too modern api (policy/v1, instead of policy/v1beta1).
• I had to use calico v3.21 instead of v3.22 because it isn't available any more due to a bug of their to redirect to some new domain etc. I have not yet reported it, yet.