3.13 fork: reportExtraMetrics produce unknown metrics

See: https://github.com/GoogleCloudPlatform/prometheus/pull/329/changes#r3629968314

> Noticed one more thing. We have to likely expand this list with new metrics https://github.com/prometheus/prometheus/blob/47ce985126421014585c0eea59febe124eb02b81/scrape/scrape.go#L2061-L2100
>
> While they have metadata upstream, it escapes scrapeloop cache export rely on.
>
> Essentially reportExtraMetrics will produce unknown and unknown:gauge. This is not a default behavior, so should be ok.

Compare the fork's reportExtraMetrics implementation with upstream prometheus/scrape/scrape.go lines 2061-2100, as linked in the issue. Identify the metrics missing from the fork's list and verify that reportExtraMetrics no longer emits unknown and unknown:gauge for them.

Written by the indexing model from the issue text.