mark opencensus deprecated (#2871)

* mark opencensus deprecated

* fix gen

* add release notes

Author: zirain

mesh/v1alpha1/config.pb.go

@@ -502,7 +502,9 @@ message MeshConfig {
       DatadogTracingProvider datadog = 6;
       // Configures a Stackdriver provider.
       StackdriverProvider stackdriver = 7;
+      // $hide_from_docs
       // Configures an OpenCensusAgent tracing provider.
+      // Deprecated: OpenCensus is deprecated, more details can be found at https://opentelemetry.io/blog/2023/sunsetting-opencensus/
       OpenCensusAgentTracingProvider opencensus = 8;
       // Configures a Apache SkyWalking provider.
       SkyWalkingTracingProvider skywalking = 9;

mesh/v1alpha1/config.proto

@@ -0,0 +1,10 @@
+apiVersion: release-notes/v2
+
+kind: feature
+area: telemetry
+issue: []
+
+releaseNotes:
+  - |
+    **Deprecated** more details can be found at https://opentelemetry.io/blog/2023/sunsetting-opencensus/, 
+    users should forward to OpenTelemetry provider.