[clang] [LifetimeSafety] Don't enable lifetime suggestions via -Weverything (PR #232300)

[Balázs Benics via cfe-commits]

steakhal wrote:

I think I'd take this also as a weak no.
And this pretty muxh matches my personal stance as well, so I'm happy that we are largely aligned on this.

I think I'll close this PR in a few days and probably move it to downstream for now.

https://github.com/llvm/llvm-project/pull/232300