Release new opentelemetry-datadog version

[alexpusch]

Current opentelemetry-datadog crate is 0.5.0 which was released 5 months ago - https://crates.io/crates/opentelemetry-datadog
Lately some interesting features were added to this crate, that we'll be happy to use. Can you release an official release of this crate?

[haixuanTao]

It would be great if we could refresh the version of many of the subcrates, to take into account the latest version of opentelemetry. But I understand that it is not easy to do version releases.

[djc]

I think we'll release another release with everything packaged up together, see #779.

[lroux-at-jellysmack]

This issue can be closed as opentelemetry-datadog v0.6 has been released. (cf. https://crates.io/crates/opentelemetry-datadog/versions)