[Code health] clang-tidy cleanup

[marcalff]

Run clang-tidy on the code base, fix issues reported.

[esigo]

Once cleaned, it's good to have a CI for this in another issue.

[github-actions]

This issue was marked as stale due to lack of activity.

[jensecrest]

Hello, I would like to work on this issue!

[dbarker]

Hi @jensecrest, Thanks!

I've logged a few issues: #3977, #3978, #3979, #3980 that would be a good place to start. Please take a look and comment on one you'd like to take on.

[dbarker]

The Github clang-tidy action is uploading warning reports and is a good place to look for current clang-tidy warnings on main.
https://github.com/open-telemetry/opentelemetry-cpp/actions/workflows/clang-tidy.yaml?query=branch%3Amain++