Fix SC2230 warning

scripts/maint/updateRustDependencies.sh

@@ -24,7 +24,7 @@ HERE=$(dirname "$(realpath "$0")")
 TOPLEVEL=$(dirname "$(dirname "$HERE")")
 TOML="$TOPLEVEL/src/rust/Cargo.toml"
 VENDORED="$TOPLEVEL/src/ext/rust/crates"
-CARGO=$(which cargo)
+CARGO=$(command -v cargo)
 
 if ! test -f "$TOML"  ; then
     printf "Error: Couldn't find workspace Cargo.toml in expected location: %s\\n" "$TOML"