src/main.rs: remove clippy::unnested_or_patterns

Signed-off-by: KOSHIKAWA Kenichi <reishoku.misc@pm.me>

src/main.rs

@@ -18,7 +18,6 @@
 #![allow(clippy::non_ascii_literal)]
 #![allow(clippy::option_if_let_else)]
 #![allow(clippy::too_many_lines)]
-#![allow(clippy::unnested_or_patterns)] // TODO: remove this when we support Rust 1.53.0
 #![allow(clippy::unused_self)]
 #![allow(clippy::upper_case_acronyms)]
 #![allow(clippy::wildcard_imports)]