giantswarm/silence-operator v0.21.0 on GitHub

Add startsAt, endsAt, and duration fields to the v1alpha2 Silence CRD for explicit silence scheduling. duration accepts weeks (w), days (d), hours (h), minutes (m), and seconds (s), each at most once and ordered largest to smallest: "7d", "2w", "1d12h". endsAt and duration are mutually exclusive. When neither is set, the valid-until annotation is used as a fallback.

Regenerate .github/workflows/zz_generated.*.yaml via devctl to use the centralized reusable workflow, removing the Node-20 mindsers/changelog-reader-action dependency.
Update Go dependencies, which resolves CVE-2026-63209 (github.com/klauspost/compress) and CVE-2026-56852 (golang.org/x/text) and removes their .nancy-ignore entries.

Quote the = scalars in the generated matchType CRD schema so the rendered chart parses under PyYAML (unblocks the HelmTemplateValidator step added in app-build-suite 2.2.0).
Fix various CVEs by updating dependencies:
Skip failing CI jobs using private secrets for external contributions from fork
Replace deprecated controller-runtime scheme.Builder with apimachinery runtime.NewSchemeBuilder
Fix gosec, goconst and errcheck linter errors in tests