Bug#993214: mpi4py: autopkgtest regression around 2021-08-25

[Graham Inggs]

Even better would be to add the following section to debian/tests/control:

# Dummy test so that changes to other packages trigger our autopkgtests
# on ci.debian.net
Test-Command: /bin/true
Depends: libpmix-dev,
    libucx-dev [amd64 arm64 ppc64el],
Restrictions: hint-testsuite-triggers

Refer 
https://salsa.debian.org/ci-team/autopkgtest/-/blob/master/doc/README.package-tests.rst