fix(macos): use rust-lld for *all* macOS targets

.cargo/config.toml

@@ -3,3 +3,10 @@ linker = "rust-lld"
 # NOTE: `rustdoc` doesn't currently respect the `linker` setting — keep an eye
 # on this issue: https://github.com/rust-lang/rust/issues/125657
 rustdocflags = ["-Clink-arg=-fuse-ld=lld"]
+
+# NOTE: Also annoyingly, `target.<cfg>` doesn't let you set `rustdocflags`, so
+# something like `[target.'cfg(target_os = "macos")']` doesn't work here and
+# this repetition is needed...
+[target.x86_64-apple-darwin]
+linker = "rust-lld"
+rustdocflags = ["-Clink-arg=-fuse-ld=lld"]