Revise the code in `opentelemetry-api/src/opentelemetry/propagators/_envcarrier.py` after recent specification updates. Specification is available [here](https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/context/env-carriers.md)
Revise the code in
opentelemetry-api/src/opentelemetry/propagators/_envcarrier.pyafter recent specification updates. Specification is available here