fix(build): clang 15 and warning fixes
Description
Clang-15 is freely available on Ubuntu 22.04. It almost works out of the box, it just requires minimal warning fixes, which indeed are legitimate.
Steps to reproduce
sudo apt install clang-15
Proposal
Fix the warnings for unused variables
No change on CI or for official compiler support. This is just for simplifying developer's life.
Functional specifications
No changes
Technical specifications
No changes
Test plan
- build + utests