Investigate why the metric on sum of bytes written to certstore is higher than expected.

[masih]

The calibnet metrics report ~20GiB of data written out to certstore. But the size of metadata store on disk is far smaller. 161 MiB size for example on the same node where metrics come from.

Understand why.

[BigLep]

2025-01-24 standup conversation: this relates to filecoin-project/lotus#12320 and isn't needed if that work is done.

Impact of deferring this work: we don't have confidence in the metrics for this area because of the discrepancy of what the metric reports vs. what we see on disk.