PR #11721: [XLA:CPU] Add  MpiCollectives to the the .pyi stubs
PR #11721: [XLA:CPU] Add  MpiCollectives to the the .pyi stubs

Imported from GitHub PR https://github.com/openxla/xla/pull/11721

we forgot this in https://github.com/openxla/xla/pull/7849.
Copybara import of the project:

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3924cc0fbbb63e9503f38a59aede3b8e817b17fa by Clemens Giuliani <clemens@inailuig.it>:

[XLA:CPU] add missing type annotations for the mpi collectives

Merging this change closes #11721

FUTURE_COPYBARA_INTEGRATE_REVIEW=https://github.com/openxla/xla/pull/11721 from inailuig:mpicollectives_pytype 3924cc0fbbb63e9503f38a59aede3b8e817b17fa
