Submit nightly eks tests to datadog

[tylerslaton]

This PR submits our test summaries to datadog so that we can keep track of the nightly eks tests overtime. It also fixes a small issue where the test-summary creation would occur (and fail) even if tests didn't run.

Note - I'll update this description when a datadog api key secret has been added so we know it is ready to merge. Its added!

Checklist

• The title of this PR would make a good line in Acorn's Release Note's Changelog
• The title of this PR ends with a link to the main issue being address in parentheses, like: This is a title (#1216). Here's an example
• All relevant issues are referenced in the PR description. NOTE: don't use GitHub keywords that auto-close issues
• Commits follow contributing guidance
• Automated tests added to cover the changes. If tests couldn't be added, an explanation is provided in the Verification and Testing section
• Changes to user-facing functionality, API, CLI, and upgrade impacts are clearly called out in PR description
• PR has at least two approvals before merging (or a reasonable exception, like it's just a docs change)

[tylerslaton]

The needs field wasn't valid here so I replaced it with a new if statement. As long as the action wasn't cancelled and the relevant step didn't get skipped then the test summary actions will run.