Description

This PR introduces a check using the cmp command in the macros responsible for publishing header files from the include directory to the __release_* directories. With this enhancement, headers are only released if their contents have changed.

This improvement addresses an issue with make's caching mechanism, which relies on file timestamps. Previously, central header files like library_version_info.h were released every time make was invoked, regardless of whether their contents had changed. This caused the timestamps to always be newer than those of the source files, triggering unnecessary target updates and negating the benefits of incremental builds.

With the proposed changes, only files that have actually changed (along with their dependencies) will be rebuilt, thereby preserving the efficiency of incremental builds.

Fixes #2944
and probably also #632

Checklist to comply with before moving PR from draft:

PR completeness and readability

• I have reviewed my changes thoroughly before submitting this pull request.
• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation to reflect the changes or created a separate PR with update and provided its number in the description, if necessary.
• Git commit message contains an appropriate signed-off-by string (see CONTRIBUTING.md for details).
• I have added a respective label(s) to PR if I have a permission for that.
• I have resolved any merge conflicts that might occur with the base branch.

Testing

does not apply - build chain only

• I have run it locally and tested the changes extensively.
• All CI jobs are green or I have provided justification why they aren't.
• I have extended testing suite if new functionality was introduced in this PR.

Performance

does not apply - build chain only

• I have measured performance for affected algorithms using scikit-learn_bench and provided at least summary table with measured data, if performance change is expected.
• I have provided justification why performance has changed or why changes are not expected.
• I have provided justification why quality metrics have changed or why changes are not expected.
• I have extended benchmarking suite and provided corresponding scikit-learn_bench PR if new measurable functionality was introduced in this PR.