CompatHelper: bump compat for "MPI" to "0.17" for package test

[github-actions]

This pull request changes the compat entry for the MPI package from 0.15, 0.16 to 0.15, 0.16, 0.17 for package test.

This keeps the compat entries for earlier versions.

Note: I have not tested your package with this new compat entry. It is your responsibility to make sure that your package tests pass before you merge this pull request.

[codecov]

Codecov Report

Merging #477 (468c396) into main (9f46c51) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #477   +/-   ##
=======================================
  Coverage   94.78%   94.78%           
=======================================
  Files         103      103           
  Lines       11396    11396           
=======================================
  Hits        10802    10802           
  Misses        594      594           

Flag	Coverage Δ
unittests	94.78% <ø> (ø)

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