PSA: Let's encrypt revocation of certificates issued with TLS-ALPN-01 challenge

[fffonion]

Let's Encrypt has announced an urgent notice on all certificates issued using TLS-ALPN-01 challenge
being revoked on 28 January 2022, due to an implementation flaw in the previous production code.

https://community.letsencrypt.org/t/questions-about-renewing-before-tls-alpn-01-revocations/170449

However the Kong ACME plugin doesn't currently support TLS-ALPN-01 challenge, thus no action is needed
on your side. However, if you are using other ACME clients in Kong with Kurbernetes with
TLS-ALPN-01 challenge, you may need to actively renew the certificates before 28 January 2022 to
avoid interruption of your service.