chore(clippy): enable and fix many stricter lints (#3783)

* chore(clippy): enable and fix many stricter lints

These ensure that the codebase uses more idiomatic, performant, and
concise language constructions.

* chore: make non-Clippy compiler warnings also deny by default

packages/app-lib/src/state/minecraft_auth.rs

@@ -1154,12 +1154,10 @@ fn get_date_header(headers: &HeaderMap) -> DateTime<Utc> {
         .get(reqwest::header::DATE)
         .and_then(|x| x.to_str().ok())
         .and_then(|x| DateTime::parse_from_rfc2822(x).ok())
-        .map(|x| x.with_timezone(&Utc))
-        .unwrap_or(Utc::now())
+        .map_or(Utc::now(), |x| x.with_timezone(&Utc))
 }
 
 #[tracing::instrument]
-#[allow(clippy::format_collect)]
 fn generate_oauth_challenge() -> String {
     let mut rng = rand::thread_rng();