Removed deprecated observability plugin (#2904)

docs/install/any-kubernetes-cluster.md

@@ -871,79 +871,3 @@ To learn more about the VMware sources and bindings, try
 You can find a number of samples for Knative Eventing
 [here](../eventing/samples/README.md). A quick-start guide is available
 [here](../eventing/getting-started.md).
-
-## Installing the Observability plugin
-
-{{< feature-state version="v0.14" state="deprecated" >}}
-
-Install the following observability features to enable logging, metrics, and
-request tracing in your Serving and Eventing components.
-
-All observibility plugins require that you first install the core:
-
-```bash
-kubectl apply --filename {{< artifact repo="serving" file="monitoring-core.yaml" >}}
-```
-
-After the core is installed, you can choose to install one or all of the
-following observability plugins:
-
-- Install [Prometheus](https://prometheus.io/) and
-  [Grafana](https://grafana.com/) for metrics:
-
-  ```bash
-  kubectl apply --filename {{< artifact repo="serving" file="monitoring-metrics-prometheus.yaml" >}}
-  ```
-
-- Install the [ELK stack](https://www.elastic.co/what-is/elk-stack)
-  (Elasticsearch, Logstash and Kibana) for logs:
-
-  ```bash
-  kubectl apply --filename {{< artifact repo="serving" file="monitoring-logs-elasticsearch.yaml" >}}
-  ```
-
-- Install [Jaeger](https://jaegertracing.io/) for distributed tracing
-
-     <!-- This indentation is important for things to render properly. -->
-
-  {{< tabs name="jaeger" default="In-Memory (standalone)" >}}
-  {{% tab name="In-Memory (standalone)" %}} To install the in-memory
-  (standalone) version of Jaeger, run the following command:
-
-```bash
-kubectl apply --filename {{< artifact repo="serving" file="monitoring-tracing-jaeger-in-mem.yaml" >}}
-```
-
-{{< /tab >}}
-
-{{% tab name="ELK stack" %}} To install the ELK version of Jaeger (needs the ELK
-install above), run the following command:
-
-```bash
-kubectl apply --filename {{< artifact repo="serving" file="monitoring-tracing-jaeger.yaml" >}}
-```
-
-{{< /tab >}} {{< /tabs >}}
-
-- Install [Zipkin](https://zipkin.io/) for distributed tracing
-
-     <!-- This indentation is important for things to render properly. -->
-
-  {{< tabs name="zipkin" default="In-Memory (standalone)" >}}
-  {{% tab name="In-Memory (standalone)" %}} To install the in-memory
-  (standalone) version of Zipkin, run the following command:
-
-```bash
-kubectl apply --filename {{< artifact repo="serving" file="monitoring-tracing-zipkin-in-mem.yaml" >}}
-```
-
-{{< /tab >}}
-
-{{% tab name="ELK stack" %}} To install the ELK version of Zipkin (needs the ELK
-install above), run the following command:
-
-```bash
-kubectl apply --filename {{< artifact repo="serving" file="monitoring-tracing-zipkin.yaml" >}}
-```
-
-{{< /tab >}} {{< /tabs >}}