This comes up during review, so instead of wasting review cycles on this, just enforce it via CI
From the clang-tidy doc:
Such use of const is usually superfluous, and can prevent valuable compiler optimizations. Does not (yet) fix trailing return types.
I have never seen it mentioned in our reviews, but my IDE flags these issues, and it can maybe save us some merge conflicts during backports.
This is a backport of core#26395
Depends on D18073