Mk/Features/lto.mk: switch LTO_UNSAFE consumers to WITHOUT_LTO

Passing -C lto=no while Cargo.toml has lto=true desyncs cargo and rustc:

= note: ld: error: [...]: Opaque pointers are only supported in -opaque-pointers mode (Producer: 'LLVM17.0.6-rust-1.77.0-stable' Reader: 'LLVM 14.0.5')

Reported by: pkg-fallout (for ~2 months)