OpenTelemetry githubreceiver silently ignores configured required_headers authentication

The OpenTelemetry Collector Contrib repository contains components for the OpenTelemetry Collector. Prior to 0.151.0, the githubreceiver validates the receiver/githubreceiver/config.go RequiredHeaders configuration at startup, but receiver/githubreceiver/trace_receiver.go handleReq() does not check those headers on incoming webhook requests. An unauthenticated sender can therefore bypass an operator's required_headers authentication control and submit arbitrary webhook payloads. When the Secret field is empty, github.ValidatePayload also skips HMAC validation, leaving the webhook endpoint without either configured authentication mechanism. Successful exploitation can inject fabricated CI/CD trace data into the observability pipeline. This issue is fixed in version 0.151.0.