Polling vaccine

[TonyCTHsu]

Motivation:

Currently, each commit is triggering a vaccine workflow run in GitLab. However, where are some caveats:

• When token is invalid, the 403 response does not failed the Gitlab job.
• Gitlab job does not acknowledge vaccine workflow failure.

Hence, the validation is included into our decision to whether a pull request can be merged.

What does this PR do?

I am improving our cross CI system by implementing a polling model to report workflow status.

This is far from ideal, but at least we get a signal from vaccine for each pull request. Current limitations of polling approach:

• Resource intensive (constant API calls)
• Potential rate limiting issues
• High latency in status updates
• Maintenance overhead
• Difficulty in handling errors or retries
• No built-in audit trail

In the future, instead of having a disconnected workflow, we can make the vaccine workflow report its status back to the original PR in Datadog/dd-trace-rb and configure GitHub required status check to include vaccine. However, such approach requires checks:write permission with an integrated Github App, that takes me time to go through the organization to setup.

Change log entry
None.