Bring back usage of system-deps

Cargo.toml

@@ -23,6 +23,12 @@ name = "retail_benchmark"
 harness = false
 required-features = ["retail_game_testing"]
 
+[build-dependencies]
+system-deps = "7"
+
+[package.metadata.system-deps]
+libunshield = { version = "1.4", feature = "game_install" }
+
 [dev-dependencies]
 hmac-sha512 = "1"
 

build.rs

@@ -2,6 +2,5 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 fn main() {
-    #[cfg(feature = "game_install")]
-    println!("cargo::rustc-link-lib=unshield");
+    system_deps::Config::new().probe().unwrap();
 }