Very slow start if a cluster not available

[dacrhu]

Describe the bug
I have 5 clusters, but one is not always available (local development cluster), the others are always online.
If this local cluster is not turned on then k9s start very slow (more then 1 minute).

To Reproduce
Steps to reproduce the behavior:

1. turn off a cluster, or make it inaccessible on the network
2. start k9s

Expected behavior
In my opinion, it should not check the availability of the cluster at startup, only when I select it on the home screen.

Versions (please complete the following information):

• OS: Fedora 39
• K9s: v0.32.3