feat: add caching for testkube binary

[devcatalin]

This PR...

Changes

Fixes

• Cache the Testkube binary in the GitHub Action testkube#4939

Checklist

• tested locally
• added new dependencies
• updated the docs
• added a test

[rangoo94]

Code LGTM, please test if the action works as expected though 👍

[itsme2980]

Hi @devcatalin , @rangoo94 Thank you for the concise support regarding this feature. I've recently had the opportunity to review your implementation, and I'd like to share some comments from my perspective. This approach is only viable once Testkube is successfully installed within the GitHub Actions (GA) workflow. This means the cache is effective only when Testkube has been installed. There's a scenario where GitHub.io might impose rate limits, rejecting installation from anonymous access, rendering this caching implementation ineffective.

I propose we implement an additional feature: allowing users to define the GitHub.io Personal Access Token (PAT) within the action.yaml. This PAT could then be used to authorize with GitHub.io, overcoming potential rate-limiting issues. For more details about the token property I mentioned, you can refer to https://github.com/actions/setup-python.

The combination of a GitHub.io token and caching would be highly beneficial. 👍