mpi4py 2023-04-24 (6860423f)

Code extracted from:

https://gitlab.kitware.com/third-party/mpi4py.git

at commit 6860423fb5bf8f55fd56f886634749a3dcfdbbb3 (for/vtk-20230424-3.1.4).

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Cc: @BenWibking
Backport: paraview/release
Backport: release