fix(clusterlib): set default timeout to 120s in run_cli

Previously, the `run_cli` method inherited the timeout behavior from the
base class, which did not set a default value. This change introduces a
default timeout of 120 seconds if none is provided, altering the method's
behavior to prevent indefinite waits and improve reliability.

Author: mkoura

cardano_node_tests/utils/custom_clusterlib.py

@@ -96,6 +96,10 @@ def cli(
         Returns:
             clusterlib.CLIOut: A data container containing command stdout and stderr.
         """
+        # Set a default timeout. This is a change of behavior compared to the base class!
+        if not timeout:
+            timeout = 120
+
         cli_args_strs_all = [str(arg) for arg in cli_args]
         if add_default_args:
             cli_args_strs_all.insert(0, "cardano-cli")