Fix flaky test in RepoPoller.Integration.GithubTest

[gausby]

Currently the test will query the GitHub API; as GitHub has a request rate limiter we see two possible outcomes from this test; either it is an error (rate limited) or "ok" with a bunch of tags.

I think we should consider skipping this test. All it really does is to test TentaCat. Perhaps we could tag it so tests that are hitting the outside world are filtered out when running the test suite while developing.

The rate-limiting is happening quite often when two or more people are working on the project from the same IP address.