Fix failing CI checks

[colbychaskell]

Multiple CI checks have been failing because of an issue using the lukka/get-cmake action in the CI workflow. The latest version of lukka/get-cmake uses node20 instead of node16 so it requires higher versions of the c standard libraries. To keep this working with the older GCC versions, I have specified the previous version of the lukka/get-cmake.

There also seems to be a new failing clang tidy check in one of the tests due to a static cast to a derived type. I assume this is due to the jobs container updating the clang tidy version. Added a NOLINT to this line to get the CI passing for now.

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• [x] Changes are described in the pull request, or an existing issue is referenced.
• [x] The test suite compiles and runs without error.
• [x] Code coverage is 100%. Test cases can be added by editing the test suite.
• [x] The source code is amalgamated; that is, after making changes to the sources in the include/nlohmann directory, run make amalgamate to create the single-header files single_include/nlohmann/json.hpp and single_include/nlohmann/json_fwd.hpp. The whole process is described here.

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• The C++11 support varies between different compilers and versions. Please note the list of supported compilers. Some compilers like GCC 4.7 (and earlier), Clang 3.3 (and earlier), or Microsoft Visual Studio 13.0 and earlier are known not to work due to missing or incomplete C++11 support. Please refrain from proposing changes that work around these compiler's limitations with #ifdefs or other means.
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[nlohmann]

Thanks a lot! L

[coveralls]

coverage: 100.0%. remained the same when pulling 1c41daada498fe99867a93062ee7677476b2228c on colbychaskell:fix-ci-get-cmake into 6eab7a2b187b10b2494e39c1961750bfd1bda500 on nlohmann:develop.