Currently unit tests fail.

Strange, maybe related to this: https://github.community/t/segmentation-fault-when-running-binary-in-a-job/18418

@horstle
I found and fixed the problem:

• the segmentation fault was caused by loading the shared library several times in quick succession. Unloading the library fixes this.
  There was also a problem with loading the 32-bit ARM lib. It throws an OSError with wrong ELF class: ELFCLASS32

I added the old get_lib_version again as a fallback.

Feel free to make a better fix, but this is good enough for me to get merged.

Ha, while looking at previous discussions I found my original code from a year ago:

#248 (comment)

@mediaminister It is supposed to fail when there is an arch mismatch, so it won't install the wrong lib. That's what this PR is trying to fix (see #413). Also, the legacy version doesn't detect an arch mismatch, so it can't be used as a check.
Instead of writing worse code to pass the tests, we should improve the tests.

I'm currently looking into AWS CodeBuild, so we can run the ARM tests on ARM hardware. I think it makes sense to have separate Github actions for each platform, then the ARM tests could be run via CodeBuild and maybe at some point the Windows tests could run on Windows (it seems that's already possible in Github, but idk if it would cost something, might look into it later). That way closing the lib wouldn't be necessary, too, although I wouldn't mind keeping that change.

SonarCloud Quality Gate failed.

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9.5% Duplication

Okay, I removed the fallback. Tests fail, but now you can see why.