add logging of headers for APIM status test

Author: nhsd-rebecca-flynn

pathology-api/lambda_handler.py

@@ -141,6 +141,7 @@ def handler(data: dict[str, Any], context: LambdaContext) -> dict[str, Any]:
     correlation_id = headers.get(_CORRELATION_ID_HEADER)
 
     if not correlation_id:
+        _logger.debug("no correlation_id in the header. Headers = %s", headers)
         return {
             "statusCode": 500,
             "headers": {"Content-Type": "application/fhir+json"},