flux-check terminates if k8s does not meet minimum required version

[drewwells]

Describe the bug a clear and concise description of what the bug is.

Flux suggests that it will not work on k8s past EOL, but says it probably still works. However, the helm chart is requiring minimum version and will not install if we don't meet that criteria.
This should be a warning rather than a fatal error

What's your helm version?

n/a

What's your kubectl version?

1.27

What's the chart version?

2.13

What happened?

flux check refuses to install 2.13 on a k8s 1.25 cluster

k -n vela-system logs -f flux2-flux-check-2hv6r
► checking prerequisites
✗ Kubernetes version v1.25.10 does not match >=1.28.0-0

What you expected to happen?

List some warnings, complain that we are still running an ancient version of k8s

How to reproduce it?

install flux2 on a cluster below 1.28

Enter the changed values of values.yaml?

n/a

Enter the command that you execute and failing/misfunctioning.

flux is installing it, so flux helmrelease resume

Anything else we need to know?

https://github.com/fluxcd-community/helm-charts/blob/main/charts/flux2/templates/pre-install-job.yaml#L36