fix: fix zkey version

Author: vivianjeng

src/utils.rs

@@ -40,10 +40,12 @@ pub fn to_element(value: Fq) -> Element {
 
 /// Download zkey from artifacts: https://snark-artifacts.pse.dev/
 pub fn download_zkey(depth: u16) -> Result<String, Box<dyn Error>> {
-    let base_url = "https://snark-artifacts.pse.dev/semaphore/latest/";
-    let filename = format!("semaphore-{}.zkey", depth);
+    let version = "4.0.0";
+    let base_url = format!("https://snark-artifacts.pse.dev/semaphore/{version}/");
+    let filename = format!("semaphore-{depth}.zkey");
+    let dest_filename = format!("semaphore-{version}-{depth}.zkey");
     let out_dir = std::env::temp_dir();
-    let dest_path = out_dir.join(filename.clone());
+    let dest_path = out_dir.join(dest_filename.clone());
     if !dest_path.exists() {
         let url = format!("{}{}", base_url, filename);
         let client = Client::new();