Remove client-specific retry attributes from server spans (per A72 tracing proposal) #8430
Description
Per the gRPC OpenTelemetry tracing proposal A72, retry information (e.g., previous-rpc-attempts, transparent-retry) is only tracked on the client side.
Currently, server spans incorrectly include client-specific retry attributes, which is not compliant with A72. This issue tracks the work required to remove these incorrect attributes and add appropriate unit tests.