Update Prometheus.erl to 4.8.2

[lhoguin]

Need to figure out the sha.

Includes the fix for deadtrickster/prometheus.erl#133

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[lhoguin]

Waiting for confirmation that the problem is gone before removing draft status.

[michaelklishin]

Just to make sure the milestone does not confuse anyone. This will also be included into 3.9.15, I already set that milestone on one of the backport PRs.