PR #96029 - pkg/util/metric: increase bucket counts for Prometheus histograms

[cockroach-teamcity]

Exalate commented:

Related PR: cockroachdb/cockroach#96029
Commit: cockroachdb/cockroach@4b32a98

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Release note (ops change): Prometheus histograms will now export
more buckets across the board to improve precision & fidelity of
information reported by histogram metrics, such as quantiles.
This will lead to an increase in storage requirements to process
these histogram metrics in downstream systems like Prometheus,
but should still be a marked improvement when compared to the
legacy HdrHistogram model. If users have issues with the precision
of these bucket boundaries, they can set the environment variable
COCKROACH_ENABLE_HDR_HISTOGRAMS=true to revert to using the
legacy HdrHistogram model instead, although this is not recommended
otherwise as the HdrHistogram strains systems like Prometheus with
excessive numbers of histogram buckets. Note that HdrHistograms are
slated for full deprecation in upcoming releases.

Jira Issue: DOC-6841