fix dynamic embedding after the Vc<T> update (vercel/turborepo#5708)

Author: ForsakenHarmony

crates/turbo-tasks-fs/src/embed/file.rs

@@ -43,7 +43,10 @@ macro_rules! embed_file {
         // check that the file exists at compile time
         let _ = include_str!(concat!(env!("CARGO_MANIFEST_DIR"), "/", $path));
 
-        turbo_tasks_fs::embed::content_from_relative_path(env!("CARGO_MANIFEST_DIR"), $path)
+        turbo_tasks_fs::embed::content_from_relative_path(
+            env!("CARGO_MANIFEST_DIR").to_string(),
+            $path.to_string(),
+        )
     }};
 }