WeylScal4 should have multi-process test cases

[Ian Hinder]

WeylScal4 currently has two tests, both of which run on a single process only. To test parallelisation, I propose that these be changed to run on two processes.

Keyword:

[Roland Haas]

The tests can be made to run on two processors but then they generate different output from a single processor run. No combination of output_ghost_points and compact_format seems to give processor independent output. Essentially two processor output contains extra empty lines (and/or the component number in a column) whose presence is considered significant by the test suite scripts. The best one can do seems to be identical up to extra empty lines when adding

IOASCII::compact_format = "yes" IOASCII::output_ghost_points = "no"

1. we want symmetry and buffer points since their behaviour changed in the past

[Roland Haas]

The tests have been allowed to run on any number of MPI ranks (for better or worse) since git hash a0de33ad "WeylScal4: Allow tests to run on any number of processes" of einsteinanalysis from 5 years ago.