Deprecate and turn down data studio GCP billing report

[BenTheElder]

1. It doesn't correctly reflect sustained use discounts
2. We will always have to maintain this versus the built-in billing reports
3. If we fix Restrict log viewing for k8s-infra-gcp-auditors #4981 we can just grant people access to browse our infra (minus sensitive logs/secrets), billing included
4. We don't have the equivalent for any other vendor, instead we open their built in billing pages in the SIG call and we have a weekly report from CNCF via ii.coop folks in #sig-k8s-infra slack channel that covers the high level spend for all vendors we have credits with (even SIG K8s Infra TLs don't have access to Azure billing currently)

/sig k8s-infra

[ameukam]

/priority important-longterm
/milestone v1.32

[BenTheElder]

These reports are wildly over-reporting spend currently by not being commitment aware. We should really take this down.

[ameukam]

/milestone clear

[BenTheElder]

cc @xmudrii @mfahlandt
(I think we should probably do this as we turn up whatever else we use, or even ahead of it, to avoid confusion about the results, or else we should fix this to include commitments correctly)

[xmudrii]

I'm +1 to turning this down ASAP, it's giving wrong results and we shouldn't use it.

[BenTheElder]

/assign @xmudrii

[ameukam]

/milestone v1.33