skip cargo items if cargo is missing

prefs/cargo.py

@@ -11,7 +11,8 @@ class CargoInstall:
 
     def run(self):
         if shutil.which('cargo') is None:
-            print(f"skip [cargo-install {self.label}]: cargo not found")
+            print(f"SKIP [cargo-install {self.label}]: cargo not found")
+            return
 
         if missing := self.crates - self.installed:
             print(f"installing missing cargo binaries: {missing}")