apmotel breaks on newer version of otel libraries

[kruskall]

Describe the bug

There was a breaking change in 1.20.0 which affected custom trace API implementations. As a result, the apmotel and similar modules using otel are currently broken and stuck with older versions.
This prevents projects depending on apmotel from bumping to newer otel versions.

Details: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.20.0

This release brings a breaking change for custom trace API implementations. Some interfaces (TracerProvider, Tracer, Span) now embed the go.opentelemetry.io/otel/trace/embedded types. Implementors need to update their implementations based on what they want the default behavior to be.

To Reproduce
Steps to reproduce the behavior:

1. create a go project using apmotel and otel
2. bump otel to 1.20.0+
3. project fails to compile

Expected behavior
No compile errors