Create NoOpPerformanceFlakinessAnalyzer if github token not found (#9015) In https://github.com/gradle/gradle/pull/8997 we query GitHub API for known flakiness issues. However sometimes `githubToken` is not set - in this case we shouldn't let the build fail.
This PR fixes the issue by creating a `NoOpPerformanceFlakinessAnalyzer` when `githubToken` is not set.
We want to mark the known performance test scenarios in the report even when they pass. This can give us insights of how the scenarios work previously. In this way, we can easily know, "this scenario fails, ah, it's marked as flaky", or, "this scenario is improved, but hold on, it's marked as flaky, let's not rebaseline it".