fix(deps): update dependency prom-client to v12

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
prom-client	dependencies	major	^11.5.3 -> ^12.0.0

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Release Notes

siimon/prom-client

v12.0.0

Compare Source

Breaking

• Dropped support for end-of-life Node.js versions 6.x and 8.x
• Dropped the previously deprecated support for positional parameters in
  constructors, only the config object forms remain.
• Default metrics are collected on scrape of metrics endpoint, not on an
  interval. The timeout option to collectDefaultMetrics(conf) is no longer
  supported or needed, and the function no longer returns a Timeout object.

Changed

• chore: remove ignored package-lock.json
• fix: process_max_fds is process limit, not OS (#​314)
• Changed Metric labelNames & labelValues in TypeScript declaration to a generic type T extends string, instead of string
• Lazy-load Node.js Cluster module to fix Passenger support (#​293)
• fix: avoid mutation bug in registry.getMetricsAsJSON()
• fix: improve performance of registry.getMetrics*
• End function of histogram startTimer, when invoked returns the number of seconds
• chore: reindent package.json
• chore: correct var name in processStartTime
• chore: add test for process_start_time_seconds
• chore: spelling corrections in README

Added

• feat: implement GC metrics collection without native(C++) modules.
• feat: implement advanced event loop monitoring

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