docs: Add legacy api gateway deprecation to Consul release notes (#20569)

* Update v1_16_x.mdx

* Update website/content/docs/release-notes/consul/v1_16_x.mdx

Co-authored-by: Jeff Boruszak <104028618+boruszak@users.noreply.github.com>

* Update v1_2_x.mdx

---------

Co-authored-by: Jeff Boruszak <104028618+boruszak@users.noreply.github.com>

website/content/docs/release-notes/consul-k8s/v1_2_x.mdx

@@ -51,7 +51,7 @@ We are pleased to announce the following Consul updates.
 
   Consul's API gateway is the recommended alternative to ingress gateway. For ingress gateway features not currently supported by API gateway, equivalent functionality will be added to API gateway over the next several releases of Consul.
 
-- **Legacy API Gateway:** The Consul AP Gateway that was previously packaged (`consul-api-gateway`) and released separately from Consul K8s is now deprecated. This is referred to as the "legacy" API Gateway.
+- **Legacy API Gateway:** The Consul API Gateway that was previously packaged (`consul-api-gateway`) and released separately from Consul K8s is now deprecated. This is referred to as the "legacy" API Gateway.
 
   The legacy API Gateway (v0.5.4) is supported with this version of Consul on Kubernetes in order to simplify the process of migrating from legacy to native API gateways.
 

website/content/docs/release-notes/consul/v1_16_x.mdx

@@ -51,6 +51,10 @@ We are pleased to announce the following Consul updates.
 
   Consul's API gateway is the recommended alternative to ingress gateway. For ingress gateway features not currently supported by API gateway, equivalent functionality will be added to API gateway over the next several releases of Consul.
 
+- **Legacy API Gateway:** The Consul API Gateway that was previously packaged as `consul-api-gateway` and released separately from Consul K8s is now deprecated. This is referred to as the "legacy" API Gateway.
+
+  This version of Consul supports v0.5.4 of the legacy API Gateway in order to simplify the process of migrating from legacy to native API gateways.
+
 - **Connect Native Golang SDK:** The Connect Native [Golang SDK](https://github.com/hashicorp/consul/tree/main/connect) is deprecated and will be removed in a future release. No further enhancements or maintenance is expected in the future releases. We will remove the SDK when the long term replacement to native application integration (such as a proxyless gRPC service mesh integration) is delivered. Refer to [GH-10339](https://github.com/hashicorp/consul/issues/10339) for additional information and to track progress toward one potential solution that is tracked as replacement functionality.
 
 - **Connect Native APIs:** The following APIs for Connect Native are deprecated: