Enable datadog chart EKS E2E tests in CI

[fanny-jiang]

What this PR does / why we need it:

Enable Datadog E2E in EKS tests in CI. E2E tests run when a branch is merged to main (ignores docs changes). E2E tests can be run manually if a commit is made to a non-main branch.

• Update test-infra-definitions runner image
• Update go dependencies
• Cleanup TODOs and remove extraneous code
• Update tests to use testing.Run() so that each subtest is printed in the go test summary

Test run: https://gitlab.ddbuild.io/DataDog/helm-charts/-/jobs/436459182

Which issue this PR fixes

(optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged)

• fixes #

Special notes for your reviewer:

Checklist

[Place an '[x]' (no spaces) in all applicable fields. Please remove unrelated fields.]

• [ ] Chart Version bumped
• [ ] Documentation has been updated with helm-docs (run: .github/helm-docs.sh)
• [ ] CHANGELOG.md has been updated
• [ ] Variables are documented in the README.md
• [ ] For Datadog Operator chart or value changes update the test baselines (run: make update-test-baselines)