Audit GCP Cloud Logs usage

We determined in https://gitlab.com/gitlab-com/gl-infra/observability/team/-/issues/4020 that we won't proceed with GCP as a log source by default. We've removed our test logs from staging but there are still quite a few logs in there.

What I'd like out of this issue is as follows:

1. What are we logging to GCP in each region?
2. Is any of that duplicated elsewhere and we can just turn off?
3. How much do we spend on all of this?