[clang] [KeyInstr][Clang][NFC] Don't set -dwarf-use-key-instructions (PR #144115)

[Orlando Cazalet-Hyams via cfe-commits]

OCHyams wrote:

> Keeping on the HELP checklines though: if you symlink clang to /bin/true then with no checklines looking for a positive match, the test will still pass, which sucks

Oh I see, I'll add a note to my TODOs to follow up

https://github.com/llvm/llvm-project/pull/144115