Fix Helm tests on release tag

[bjee19]

Fix Helm tests on release tag and replace cut commands.

Problem: Helm tests fail on release tag because the kind load command did not work when the provided images spanned multiple lines. Also, cut commands did not work as input was not a single value.

Solution: Instead of using steps.*.outputs.tags which can output multiple lines, changed to use the hardcoded path to the image and a specific version.

Testing: Manually verified on fork that the change works on a release tag.

Closes #1190

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork

[lucacome]

LGTM! 🚀