add deprecation notices for net-http01 (#5762)

docs/install/yaml-install/serving/install-serving-with-yaml.md

@@ -174,7 +174,9 @@ The following tabs expand to show instructions for installing each Serving exten
     Follow the documentation in [Enabling automatic TLS certificate provisioning](../../../serving/encryption/enabling-automatic-tls-certificate-provisioning.md)
     for more information.
 
-=== "TLS with HTTP01"
+=== "TLS with HTTP01 (deprecated)"
+
+    ⚠️ The net-http01 component is deprecated and will no longer be shipped in Knative v1.13. For a timeline see: https://github.com/knative/serving/issues/14640. We recommend using cert-manager and configure it to use HTTP01.
 
     Knative supports automatically provisioning TLS certificates using Encrypt HTTP01 challenges. The following commands install the components needed to support TLS.