mark opencensus deprecated

[zirain]

xref: https://opentelemetry.io/blog/2023/sunsetting-opencensus/

[howardjohn]

can we add a release note telling users what to do (move to otel, I assume).

otherwise LGTM

[costinm]

Looks good - should we add notes to the other providers and indicate the intent to deprecate and warn users off ? I assume there are no objections to adopting otel and using
otel collectors as integration point with vendor protocols.

Also not sure if deprecate + hide from docs is the correct path - normally we want users to see the field and deprecation warning in the generated docs.

[zirain]

Looks good - should we add notes to the other providers and indicate the intent to deprecate and warn users off ? I assume there are no objections to adopting otel and using otel collectors as integration point with vendor protocols.

Also not sure if deprecate + hide from docs is the correct path - normally we want users to see the field and deprecation warning in the generated docs.

Plan to add warning notes in istioctl analysis