Swap std::is_trivial with non deprecated traits

[P3RK4N]

Summary

This PR resolves the deprecation warning triggered by the use of std::is_trivial<LineCol> in RapidYAML headers when building on C++26 standard.

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Warning Details

During build, the following warning was emitted:

/bin/_deps/rapidyaml-src/src/c4/yml/common.hpp:291:20: warning: 'is_trivial[c4::yml::LineCol]' is deprecated:
Consider using is_trivially_copyable<T>::value && is_trivially_default_constructible<T>::value instead [-Wdeprecated-declarations]

On line:

static_assert(std::is_trivial<LineCol>::value, "LineCol not trivial");

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Notes

• No functional changes to RapidYAML.
• Build output is now clean on all supported platforms/compilers.
• Future-proof against deprecated traits warnings in C++26, but still complies with C++11.

[P3RK4N]

Hey @biojppm, sorry for being unresponsive!
So, coverage tests are failing due to missing token, I guess we are fine with that.
Regarding clang_tidy test, we can either supress the warning or split the static assert into 2 separate ones.

Let me know how do you want me to proceed.

[biojppm]

Please split.

[biojppm]

Thanks!