Disable LLD

With rust-lang/rust#124129, x64 linux switches
to use LLD by default, but this causes dependency issues on NixOS.
Disable LLD for now.

This is tracked by rust-lang/rust#125321.

Author: nbdd0121

.cargo/config.toml

@@ -1,2 +1,5 @@
 [env]
 RUSTC_BOOTSTRAP = "1"
+
+[build]
+rustflags = ["-Zlinker-features=-lld"]