Fix issue 2279: Implement singleton pattern for Telemetry class to prevent multiple OtelBatchSpanProcessor threads

Co-Authored-By: Joe Moura <joao@crewai.com>

tests/telemetry/test_telemetry_singleton.py

@@ -0,0 +1,41 @@
+import threading
+import pytest
+from crewai.telemetry import Telemetry
+
+
+def test_telemetry_singleton():
+    """Test that Telemetry is a singleton and only one instance is created."""
+    # Create multiple instances of Telemetry
+    telemetry1 = Telemetry()
+    telemetry2 = Telemetry()
+    
+    # Verify that they are the same instance
+    assert telemetry1 is telemetry2
+    
+    # Verify that the BatchSpanProcessor is initialized only once
+    # by checking that the provider is the same
+    assert telemetry1.provider is telemetry2.provider
+
+
+def test_telemetry_thread_safety():
+    """Test that Telemetry singleton is thread-safe."""
+    # List to store Telemetry instances created in threads
+    instances = []
+    
+    def create_telemetry():
+        instances.append(Telemetry())
+    
+    # Create multiple threads that create Telemetry instances
+    threads = []
+    for _ in range(10):
+        thread = threading.Thread(target=create_telemetry)
+        threads.append(thread)
+        thread.start()
+    
+    # Wait for all threads to complete
+    for thread in threads:
+        thread.join()
+    
+    # Verify that all instances are the same
+    for instance in instances[1:]:
+        assert instance is instances[0]