Fix Python 3.10 compatibility: Replace datetime.UTC with timezone.utc

- Created datetime_compat module to provide UTC constant using timezone.utc
- Updated all direct UTC imports to use compatibility module
- Added tests to verify UTC timezone compatibility
- Fixes #2171

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

tests/utilities/test_datetime_compat.py

@@ -0,0 +1,14 @@
+"""Test datetime compatibility module."""
+from datetime import timezone
+
+from crewai.utilities.datetime_compat import UTC
+
+
+def test_utc_timezone_compatibility():
+    """Test that UTC timezone is compatible with both Python 3.10 and 3.11+"""
+    assert UTC == timezone.utc
+    assert UTC.tzname(None) == "UTC"
+    # Verify it works with datetime.now()
+    from datetime import datetime
+    dt = datetime.now(UTC)
+    assert dt.tzinfo == timezone.utc