[Bug]:unknown metric: [mem3,shard_cache,hit]

### Version

3.5.0

### Describe the problem you're encountering

Every day one of my CouchDB servers registers millions of "unknown metric" errors.
Example: "unknown metric: [mem3,shard_cache,hit]"
We do not have any 3rd party monitoring tools.
This is a fresh install of CouchDB 3.5.0 and a single node.

### Expected Behaviour

I expect for their not to be millions of these errors as this does not happen on our other CouchDB servers even after a fresh install.

### Steps to Reproduce

_No response_

### Your Environment

_No response_

### Additional Context

_No response_

Start by investigating CouchDB 3.5.0 metric registration and logging for mem3, shard_cache, and hit on a fresh single-node installation. Reproduce the daily unknown-metric errors and compare the behavior with the reporter's other CouchDB servers. Done means the valid metric no longer produces millions of erroneous unknown-metric errors.

Written by the indexing model from the issue text.