Release request: tag v0.21.2 (includes KernelTainted from #844/#847)

[arunsrini3082]

Summary

Could a maintainer cut a new tagged release? node_exporter PR#3745 is blocked because it depends on KernelTainted() and the linux build-tag fix, which are merged on master but not yet in any tagged release.

Could a maintainer cut a new tagged release? node_exporter PR prometheus/node_exporter#3745 depends on KernelTainted() and the linux build-tag fix, both merged to master but not yet in any tagged release.

Context

node_exporter#3745 adds a tainted collector that reads /proc/sys/kernel/tainted via procfs.FS.KernelTainted(). It is currently pinned to a pseudo-version:

github.com/prometheus/procfs v0.21.2-0.20260717070424-0cd18237af6e

Upstream projects typically prefer proper semver tags over pseudo-versions in go.mod.

What's needed

A tagged release (e.g. v0.21.2) that includes at minimum:

• procfs: add KernelTainted() to parse /proc/sys/kernel/tainted #844 — procfs: add KernelTainted() to parse /proc/sys/kernel/tainted (1de9cf3)
• kernel_tainted: use linux build tag instead of !windows #847 — kernel_tainted: use linux build tag instead of !windows (0cd1823)
  Latest tag is v0.21.1 (3c943fd); master is 11 commits ahead.

Happy to help test or update node_exporter's go.mod once the tag is published.