Ensure unit tests don't fail silently

[n-claes]

PR description

Apparently for some cases when unit tests fail pFUnit flags them as failures in the terminal, but does not properly exit with an error. This affected two minor unit tests which have been silently failing for the past month. This PR ensures a proper exit by piping the terminal output to a log file, grepping for failures and exiting with a 1 status if these are found.

Bugfixes

Legolas

• Fixed two unit tests that were silently failing
• Ensure proper exit 1 status when the unit testing suite fails

For future reference: Goddard-Fortran-Ecosystem/pFUnit#423

Testing

Unit tests

• Fixed the two failing minor tests
• CI now uses gcc-9, gcc-10, gcc-11 and gcc-12 for unit testing (coverage only with 11)

[codecov]

Codecov Report

Merging #138 (19281e4) into develop (9fd0bdc) will increase coverage by 0.00%.
The diff coverage is 100.00%.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop     #138   +/-   ##
========================================
  Coverage    90.69%   90.69%           
========================================
  Files          158      158           
  Lines         8965     8967    +2     
========================================
+ Hits          8131     8133    +2     
  Misses         834      834           

Flag	Coverage Δ
legolas	93.13% <100.00%> (+<0.01%)	⬆️
pylbo	86.33% <ø> (ø)

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