Update nats_exporter from 0.16.0 to 0.18.0

[prometheus-rpm-bot]

https://github.com/nats-io/prometheus-nats-exporter/releases/tag/v0.18.0
Release notes:

  ## What's Changed

  - Add account details collector iterating over jwt details by @roeschter in #375
  - Add JetStream stream source metrics by @Maia-Tech in #365
  - Add JetStream mirror lag metrics by @roeschter in #379
  - Export account resource consumption and limits by @MattiasAng in #322
  - Add account name to metrics key by @roeschter in #374
  - Add stream message limit metric by @tilakraj94 in #341
  - Bump golang.org/x/crypto from 0.38.0 to 0.45.0 by @dependabot in #378
  - Bump golangci/golangci-lint-action from 8 to 9 by @dependabot in #377
  - Bump actions/setup-go from 5 to 6 by @dependabot in #371
  - Bump actions/checkout from 4 to 5 by @dependabot in #369
  - Bump golang from 1.24.2-bullseye to 1.24.3-bullseye in /cicd by @dependabot
  - Bump golang from 1.24.3-bullseye to 1.24.5-bullseye in /cicd by @dependabot
  - Bump golang from 1.24.5-bullseye to 1.24.6-bullseye in /cicd by @dependabot
  - Bump alpine from 3.21.3 to 3.22.0 in /cicd by @dependabot
  - Bump alpine from 3.22.0 to 3.22.1 in /cicd by @dependabot in #366
  - Bump alpine from 3.22.1 to 3.22.2 in /cicd by @dependabot