chore: move xray and xray-lambda propagators to contrib

[pichlermarc]

Which problem is this PR solving?

• the spec prohibits us from hosting vendor propagators in the core repo. From the spec:

Additional Propagators implementing vendor-specific protocols such as AWS
X-Ray trace header protocol MUST NOT be maintained or distributed as part of
the Core OpenTelemetry repositories.

Short description of the changes

• moves the xray and xray lambda propagators back to contrib (see chore: move xray propagators back to contrib opentelemetry-js-contrib#2411)
• deletes them here

[pichlermarc]

I will take this out of draft once open-telemetry/opentelemetry-js-contrib#2411 is merged 🙂