use correct cache URL

src/main.rs

@@ -65,9 +65,6 @@ struct Input {
     /// Must be in UTF-8
     #[parser(key_parser)]
     key: CacheKey,
-    /// A server url to upload the cache to
-    #[default_str("${{ forgejo.api_url }}")]
-    base_url: String,
 }
 
 #[derive(Debug, thiserror::Error)]
@@ -127,11 +124,7 @@ impl Client {
 
 fn main() {
     // parse inputs
-    let Input {
-        path,
-        key,
-        base_url,
-    } = Input::get();
+    let Input { path, key } = Input::get();
     let actions_token = actions_token().unwrap();
 
     // set up http client
@@ -142,7 +135,7 @@ fn main() {
         .unwrap();
     let client = Client {
         http_client,
-        base_url,
+        base_url: std::env::var("ACTIONS_CACHE_URL").unwrap(),
     };
 
     // collect and compress the cached files