Fix IndexError: list index out of range in resampler

[llucax]

When awaiting the resamplers to finish resampling, we need to make a copy of the resamplers dict, because new resamplers could be added or removed while we are awaiting, which would cause the results to be out of sync.

Here is a traceback of an instance of this bug:

2024-11-25 12:45:26,052,52 WARNING  [_broadcast.py:416] Broadcast receiver [Broadcast:GrpcStreamBroadcaster-raw-component-data-2006:_Receiver] is full. Oldest message was dropped.
2024-11-25 12:45:26,052,52 ERROR    [_resampling.py:195] The resample() function got an unexpected error, restarting...
Traceback (most recent call last):
  File "/home/marenz/frequenz/sdk/src/frequenz/sdk/microgrid/_resampling.py", line 179, in _log_resampling_task_error
    resampling_task.result()
  File "/home/marenz/frequenz/sdk/src/frequenz/sdk/timeseries/_resampling.py", line 509, in resample
    {
  File "/home/marenz/frequenz/sdk/src/frequenz/sdk/timeseries/_resampling.py", line 514, in <dictcomp>
    if isinstance(results[i], (Exception, asyncio.CancelledError))
                  ~~~~~~~^^^
IndexError: list index out of range

[llucax]

Updated to:

• Copy only the keys
• Use zip()
• Remove the unnecessary cast

[ela-kotulska-frequenz]

Thanks!