Use oversubscribe option only for Dask clusters

[srmnitc]

The MPI run command uses oversubscribe option which is only useful if Dask clusters are used. However, this option fails with mpich. I added a small workaround, which only uses this option if a Dask cluster is used.

This fix could be the solution for this and this.

@niklassiemer Could you please help with the tag for black formatting?

[niklassiemer]

Sure, I completely forgot to push that tag and workflow to all repos.

[jan-janssen]

The MPI run command uses oversubscribe option which is only useful if Dask clusters are used. However, this option fails with mpich. I added a small workaround, which only uses this option if a Dask cluster is used.

To my knowledge the whole trick of communicating via stdin and stdout only works with OpenMPI but not mpich. At least for large structures - that is why I did not care about mpich support so far.

[srmnitc]

I was not aware of this; then there is really need for this change. I will run a few more tests before we go ahead and close it.

[jan-janssen]

I was not aware of this; then there is really need for this change. I will run a few more tests before we go ahead and close it.

As I see no progress on this pull request I close it now. Feel free to re-open it.