[clang-tools-extra] [clang-tidy] bugprone-assert-side-effect non-const operator methods (PR #71974)

[Piotr Zegar via cfe-commits]

https://github.com/PiotrZSL approved this pull request.

Update documentation of this check to mention this, and update release notes.
Code looks fine.

https://github.com/llvm/llvm-project/pull/71974