Auto merge of #126701 - onur-ozkan:build-lld-if-enabled, r=Kobzol

ignore `llvm::Lld` if lld is not enabled

People are having trouble ([ref. zulip thread](https://rust-lang.zulipchat.com/#narrow/stream/326414-t-infra.2Fbootstrap/topic/MSVC.20Runtime.20mismatch.20when.20building.20LLD)) when they don't want to build `lld` for their custom distribution tarballs even with `lld = false` in their config.toml. This is because it is not controlled by `lld_enabled` flag. This change ensures that `llvm:Lld` is controlled by lld configuration.

Additionally, `lld = true` is set by default for dist profile, because we have been building it all along and this maintains that behavior.

try-job: x86_64-mingw