feat(flow): log each flow method execution at INFO

Flows emit a Rich console message when they start ('Flow started with
ID: …') but produce no further log line until the next significant
event. When a flow appears to hang, this makes it hard to tell which
@start/@listen method is currently running.

Add a single INFO log at the entry of _execute_method that surfaces
the active method name. This works for both @start methods and
listeners since both paths funnel through _execute_method.

lib/crewai/src/crewai/flow/flow.py

@@ -2633,6 +2633,7 @@ class Flow(BaseModel, Generic[T], metaclass=FlowMeta):
             the event_id of the MethodExecutionFinishedEvent, or None if events
             are suppressed.
         """
+        logger.info("Executing flow method: %s", method_name)
         try:
             dumped_params = {f"_{i}": arg for i, arg in enumerate(args)} | (
                 kwargs or {}