Failing to build on MacOS due to missing include of unordered_map

[miles200]

We're experiencing a build issue using Github Actions on macOS due to the following:

/Users/runner/work/Segs/Segs/3rd_party/lua_sol2/include/sol/sol.hpp:21158:23: error: no template named 'unordered_map' in namespace 'std'
                                static const std::unordered_map<string_view, lua_CFunction> calls {
                                             ~~~~~^ 

Noticed this was fixed on #1034 so we pulled in the latest version of sol2 but are still experiencing the above. It looks like the added #include <unordered_map> in the newer version of sol2 appears after line 21158 where the above occurs. (I think?)

Full build is here https://gist.github.com/miles200/5196567f6ea6cda9c79c3ca057b956b2