Fix build issues

[takumiSudo]

1. Cedar-Agent Update:

   • Updated the version of cedar-agent to "0.2.0".

2. Code Changes in api.rs:

   • Modified the code within the api.rs file to resolve type errors that were occurring during the build process.
   • During the initial build process cargo build, cedar-agent failed to compile due to a Type error in the tinytodo/src/api.rs code:

Original Code:

fn respond(msg: Result<impl Serialize, Error>) -> impl warp::Reply {
   match msg {
       Ok(msg) => Ok(warp::reply::json(&msg)),
       Err(error) => Ok(warp::reply::json(&ErrorMsg { error })),
   }
}

Refined Code:

fn respond(msg: Result<impl Serialize, Error>) -> impl warp::Reply {
    match msg {
        Ok(msg) => warp::reply::json(&msg),
        Err(error) => warp::reply::json(&ErrorMsg { error }),
    }
}

which removed the OK(...) wrapper.