feat(test.rs): Clone with a filter to further reduce download costs

Author: tempdragon

build_system/src/test.rs

@@ -503,6 +503,7 @@ fn setup_rustc(env: &mut Env, args: &TestArg) -> Result<(), String> {
             &"https://github.com/rust-lang/rust.git",
             &"--depth",
             &"1",
+            &"--filter=blob:limit=0",
         ],
         None,
         Some(env),