Fix deleting clusters with a non-active status

[cPu1]

Description

eksctl was failing to delete clusters that are in a non-active state, e.g., CREATING.
This was caught in the before_active integration test.

This changelist checks if the cluster is operable before creating tasks for pod identity deletion.

Checklist

• Added tests that cover your change (if possible)
• Added/modified documentation as required (such as the README.md, or the userdocs directory)
• Manually tested
• Made sure the title of the PR is a good description that can go into the release notes
• (Core team) Added labels for change area (e.g. area/nodegroup) and kind (e.g. kind/improvement)

BONUS POINTS checklist: complete for good vibes and maybe prizes?! 🤯

• Backfilled missing tests for code in same general area 🎉
• Refactored something and made the world a better place 🌟