Fix import when trace is missing from opentelemetry (elastic#2694) (elastic#2705)

(cherry picked from commit de6ed82)

Co-authored-by: Nicolò Boschi <[email protected]>

Author: github-actions[bot]

elasticsearch/_otel.py

@@ -25,7 +25,7 @@
     from opentelemetry import trace
 
     _tracer: trace.Tracer | None = trace.get_tracer("elasticsearch-api")
-except ModuleNotFoundError:
+except ImportError:
     _tracer = None
 
 from elastic_transport import OpenTelemetrySpan