fix: use rustup toolchain add

Author: brynblack

scripts/brew-install.sh

@@ -23,7 +23,7 @@ brew link --overwrite rustup-init
 echo "Running rustup-init"
 rustup-init --default-toolchain 1.68.2 -y
 echo "Adding x86_64-apple-darwin as target"
-rustup add x86_64-apple-darwin
+rustup toolchain install x86_64-apple-darwin
 echo "Adding aarch64-apple-darwin as target"
-rustup add aarch64-apple-darwin
+rustup toolchain install aarch64-apple-darwin
 echo "Completed brew setup"