Fix log propagation issue (#498)

We were not propagating logs, which led to people who had custom log
handlers to miss Cosmos events.

Closes: #476

cosmos/log.py

@@ -24,7 +24,6 @@ def get_logger(name: str | None = None) -> logging.Logger:
     [2023-08-09T14:20:55.532+0100] {subprocess.py:94} INFO - (astronomer-cosmos) - 13:20:55  Completed successfully
     """
     logger = logging.getLogger(name)
-    logger.propagate = False
     formatter: logging.Formatter = CustomTTYColoredFormatter(fmt=LOG_FORMAT)  # type: ignore
     handler = logging.StreamHandler()
     handler.setFormatter(formatter)

tests/test_log.py

@@ -9,5 +9,6 @@ def test_get_logger():
     assert custom_string not in standard_logger.handlers[0].formatter._fmt
 
     custom_logger = get_logger("cosmos-log")
+    assert custom_logger.propagate is True
     assert custom_logger.handlers[0].formatter.__class__.__name__ == "CustomTTYColoredFormatter"
     assert custom_string in custom_logger.handlers[0].formatter._fmt