Update to OTLP 1.1

[jmacd]

Is your feature request related to a problem? Please describe.
We desire to support features enabled in OTLP 1.1. In particular, the new Span Flags field.

Describe the solution you'd like
Apply the update.

Describe alternatives you've considered
n/a

Additional context
https://github.com/open-telemetry/opentelemetry-proto/blob/main/CHANGELOG.md#110---2024-01-10

[jmacd]

This will address #9550