Fix Boost tests

[jngrad]

Fixes #3426

[codecov]

Codecov Report

Merging #3427 into python will decrease coverage by <1%.
The diff coverage is 100%.

@@          Coverage Diff           @@
##           python   #3427   +/-   ##
======================================
- Coverage      86%     86%   -1%     
======================================
  Files         534     534           
  Lines       25099   25099           
======================================
- Hits        21703   21702    -1     
- Misses       3396    3397    +1

Impacted Files	Coverage Δ
src/utils/tests/matrix_vector_product.cpp	100% <ø> (ø)	⬆️
src/core/unit_tests/grid_test.cpp	100% <100%> (ø)	⬆️
src/utils/tests/interpolation_test.cpp	100% <100%> (ø)	⬆️
src/utils/tests/int_pow_test.cpp	100% <100%> (ø)	⬆️
src/core/observables/ComForce.hpp	91% <0%> (-9%)	⬇️

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[jngrad]

@junghans I've tried cherry-picking this PR locally on top of 4.1.2 and it merged cleanly. You should be able to use it directly in 4.1.2 builds, without an if condition on i586 (the tests were wrong for all archs).

[junghans]

Seems to work! collision_detection still fails reliably.