fix(deps): update module github.com/prometheus/client_golang to v1.21.1

[renovate-bot]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
github.com/prometheus/client_golang	v1.21.0 -> v1.21.1

---

Release Notes

prometheus/client_golang (github.com/prometheus/client_golang)

v1.21.1: / 2025-03-04

Compare Source

This release addresses a major performance regression introduced in #​1661 -- thanks to all who reported this quickly:
@​chlunde, @​dethi, @​aaronbee @​tsuna 💪🏽. This patch release also fixes the iOS build.

We will be hardening the release process even further (#​1759, #​1761) to prevent this in future, sorry for the inconvenience!

The high concurrency optimization is planned to be eventually reintroduced, however in a much safer manner, potentially in a separate API.

• [BUGFIX] prometheus: Revert of Inc, Add and Observe cumulative metric CAS optimizations (#​1661), causing regressions on low concurrency cases #​1757
• [BUGFIX] prometheus: Fix GOOS=ios build, broken due to process_collector_* wrong build tags. #​1758

All commits

• Revert "exponential backoff for CAS operations on floats" and cut 1.21.1 by @​bwplotka in https://github.com/prometheus/client_golang/pull/1757
• Fix ios build for 1.21.1 by @​bwplotka in https://github.com/prometheus/client_golang/pull/1758

Full Changelog: prometheus/client_golang@v1.21.0...v1.21.1

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• If you want to rebase/retry this PR, check this box

---

This PR was generated by Mend Renovate. View the repository job log.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.02%. Comparing base (3c135b1) to head (2a1b616).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #6802   +/-   ##
=======================================
  Coverage   96.02%   96.02%           
=======================================
  Files         364      364           
  Lines       20690    20690           
=======================================
  Hits        19867    19867           
  Misses        628      628           
  Partials      195      195           

Flag	Coverage Δ
badger_v1	9.81% <ø> (ø)
badger_v2	1.89% <ø> (ø)
cassandra-4.x-v1-manual	14.86% <ø> (ø)
cassandra-4.x-v2-auto	1.88% <ø> (ø)
cassandra-4.x-v2-manual	1.88% <ø> (ø)
cassandra-5.x-v1-manual	14.86% <ø> (ø)
cassandra-5.x-v2-auto	1.88% <ø> (ø)
cassandra-5.x-v2-manual	1.88% <ø> (ø)
elasticsearch-6.x-v1	19.19% <ø> (ø)
elasticsearch-7.x-v1	19.27% <ø> (ø)
elasticsearch-8.x-v1	19.44% <ø> (ø)
elasticsearch-8.x-v2	1.89% <ø> (ø)
grpc_v1	10.86% <ø> (ø)
grpc_v2	7.86% <ø> (ø)
kafka-3.x-v1	10.11% <ø> (ø)
kafka-3.x-v2	1.89% <ø> (ø)
memory_v2	1.89% <ø> (ø)
opensearch-1.x-v1	19.32% <ø> (ø)
opensearch-2.x-v1	19.32% <ø> (ø)
opensearch-2.x-v2	1.89% <ø> (ø)
tailsampling-processor	0.48% <ø> (ø)
unittests	94.91% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.