Specify indexing arguments to torch.meshgrid

[TomTomRixRix]

Describe the bug
When calling the convenience DAS reconstruction function I get the following warning.

UserWarning: torch.meshgrid: in an upcoming release, it will be required to pass the indexing argument. (Triggered internally at ../aten/src/ATen/native/TensorShape.cpp:3587.)
  return _VF.meshgrid(tensors, **kwargs)  # type: ignore[attr-defined]

We should probably specify the indexing arguments already in the torch.meshgrid function to avoid troubles when upgrading torch.

Specify a priority (low, medium, high)
low

To Reproduce
Steps to reproduce the behavior:

1. pip install simpa==0.9.1
2. In your script, call sp.reconstruct_delay_and_sum_pytorch

Current Behavior
Warning is thrown.

Expected behavior
No warning is thrown.

I get this warning when using simpa 0.9.1. It might have been addressed already with simpa 1.0?