Invalid trace when Npsql and EFCore instrumentation are enabled

[lachmatt]

See details in open-telemetry/opentelemetry-dotnet-contrib#2792

This issue is here in case we need follow up work.

[Kielek]

Ref: open-telemetry/opentelemetry-dotnet-contrib#2829

Released as 1.12.0-beta.2, today.

[lachmatt]

Issue still exists after OpenTelemetry.Instrumentation.EntityFrameworkCore was updated to 1.12.0-beta.2.