feat: ci test report

[oycyc]

Description of the change

Using this action https://github.com/masterpointio/github-action-opa-rego-test to generate a report on the test results, coverage, and also reports on the policies that are being untested.

Totally up to y'all if you want to introduce this if it seems helpful! I thought to contribute this since we made this for another project and it's open source.

Here is an example of it in use for this repository in a fork oycyc#1

It is failing in this PR because it doesn't have permission to write a PR comment since this PR is coming from an external source (a fork). If this is merged, all future PR's should automatically write a comment like this example above.

Checklist

Please make sure that the proposed change checks all the boxes below before requesting a review:

• Each new policy has corresponding tests.
• All the tests pass.
• The pull request is opened against the main branch.
• The pull request is no longer marked as a draft.
• You agree to license your contribution under the MIT license to Spacelift (not required for Spacelift employees).

If the proposed change is ready to be merged, please request a review from @spacelift-io/solutions-engineering. Someone will review and merge the pull request.

Spacelift employees should request reviews from the relevant engineers and are allowed to merge pull requests after they got at least one approval.

Thank you for your contribution! 🙇

[oycyc]

https://github.com/spacelift-io/spacelift-policies-example-library/actions/runs/10527640276/job/29171261854?pr=72#step:3:13968

It is failing in this PR because it doesn't have permission to write a PR comment since this PR is coming from an external source (a fork). If this is merged, all future PR's will automatically write a comment like this example oycyc#1 (comment).