GHA: Fix OpenMP not found on macos

[dweindl]

• Ensure cmake can find OpenMP
• Assert that amici was compiled with OpenMP support
• Update installation guide

Fixes #2182

[codecov]

Codecov Report

Merging #2207 (8aad4a9) into develop (8b836ae) will decrease coverage by 22.73%.
The diff coverage is n/a.

Additional details and impacted files

@@             Coverage Diff              @@
##           develop    #2207       +/-   ##
============================================
- Coverage    76.53%   53.80%   -22.73%     
============================================
  Files           82       34       -48     
  Lines        15012     5652     -9360     
============================================
- Hits         11489     3041     -8448     
+ Misses        3523     2611      -912     

Flag	Coverage Δ
cpp	?
cpp_python	?
petab	53.80% <ø> (ø)
python	?
sbmlsuite	?

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see 66 files with indirect coverage changes

[FFroehlich]

brew link openmp and brew link boost would also work but adds those paths globally. $(brew --prefix) won't work with non-default install directories.

[dweindl]

brew link openmp and brew link boost would also work but adds those paths globally.

Okay, will add that to installation guide.

$(brew --prefix) won't work with non-default install directories.

I am not really familiar with brew. Do you mean there are cases where brew install something will install the package somewhere else than $(brew --prefix)? Or only if other options are passed?

[FFroehlich]

$(brew --prefix) won't work with non-default install directories.

I am not really familiar with brew. Do you mean there are cases where brew install something will install the package somewhere else than $(brew --prefix)? Or only if other options are passed?

thought it was possible, but it's actually not. $(brew --prefix) should always work.