cert-manager v1.21.1

This patch release addresses several regressions introduced in v1.21.0, including a controller panic and secret informer issues. It also improves the reliability of ACME Issuers and includes critical security updates for underlying dependencies.

Prevent controller panic for certificates with disabled renewal policies — This fixes a critical regression where the controller could crash if certificates were configured not to renew, ensuring stability for manual certificate management workflows.

Fix log spam and Secret informer event drops — Resolves a regression that flooded logs with noise and risked missing important secret updates, ensuring the controller remains responsive and logs stay actionable.

Automatic recovery for ACME Issuers waiting on DNS-01 Secrets — Issuers will now correctly recover and validate once their required DNS-01 secrets are created, removing the need for manual restarts or resource re-applications.

Security patches for core dependencies and base images — Protects the certificate management infrastructure by addressing vulnerabilities in core dependencies like gRPC and CEL-go.