fix(synthetics): Adjust timeframes loop to include child objects

[elx-bob]

what

• Change loop to use child objects instead of timeframes object.
• Update Datadog provider requirements for synthetics
• Fix broken test

why

• Synthetics options.scheduling.timeframes was incorrectly treated as an object, and is now correctly treated as a list of objects, as specified in the API documentation
• Improved API validation at the server level uncovered a bug in the Datadog provider for synthetic tests, which was fixed in provider v3.43.1
• The test requirement that the monitor had no tags was overly strict, requiring a nil output rather than an empty one, causing properly working code to be marked as failing

references

• Closes Advanced Scheduling for Datadog Synthetics Non-Functional #100
• Needed to fix API Multi-step Synthetics test creation failed with extracted_value DataDog/terraform-provider-datadog#2531

[RoseSecurity]

/terratest

[GabisCampana]

@Nuru

[Nuru]

/terratest

[Nuru]

/terratest

[Nuru]

@elx-bob Thank you for this PR.

At the moment, the automated tests are failing. The test failures do not appear to be related to this PR, but still, we do not like to accept/merge PRs when the tests are failing. I am looking into it; no further action is required on your part at this time.

[Nuru]

/terratest

[github-actions]

These changes were released in v1.4.2.