[v2.8] fix: Replace unapproved GH Actions with approved ones

[yiannistri]

What this PR does / why we need it:

Replace unapproved GH Actions with approved ones. To enhance security, the 3rd-party GH Action used to install kind is pinned to a commit SHA. Note that dependabot will update both the commit SHA and the human-readable value next to it.

Which issue(s) this PR fixes
Issue rancher/highlander#89

Special notes for your reviewer:

• actions/checkout has been updated to v4 to eliminate Node runtime version warnings
• actions/setup-go has been updated to v5 to eliminate Node runtime version warnings
• Upon checkout, credentials are not being persisted since the git commands will occur on a different repo (bot's fork)

Checklist:

• squashed commits into logical changes
• includes documentation
• adds unit tests
• adds or updates e2e tests
• backport needed