resources-report: add whitelist functionality for certain resources

Created by: bobheadxi

Follow-up to https://github.com/sourcegraph/sourcegraph/pull/10784 - the first iteration of the action reports everything it finds that was created in the last x hours. However, some autoscaling services can generate a lot of noise in the report - most notably buildkite, where fluctuations in resources used is expected.

This filtering could be done via some custom labelling scheme (for example, "resources-report": "ignore") or similar