x/website: deprecated opentracing/opentracing-go package should be removed from the main page

[habiiev]

What is the URL of the page with the issue?

https://go.dev

Screenshot

opentracing/opentracing-go is deprecated, I think it should be removed

[gopherbot]

Change https://go.dev/cl/421894 mentions this issue: _content: replace opentracing with opentelemetry