Fix new clippy lint

crates/ruma-common/src/identifiers/key_id.rs

@@ -84,7 +84,7 @@ impl<A, K: ?Sized> Eq for KeyId<A, K> {}
 
 impl<A, K: ?Sized> PartialOrd for KeyId<A, K> {
     fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
-        PartialOrd::partial_cmp(self.as_str(), other.as_str())
+        Some(self.cmp(other))
     }
 }
 

crates/ruma-common/src/identifiers/room_version_id.rs

@@ -123,7 +123,7 @@ impl PartialOrd for RoomVersionId {
     /// specification. This implementation only exists to be able to use `RoomVersionId`s or
     /// types containing `RoomVersionId`s as `BTreeMap` keys.
     fn partial_cmp(&self, other: &RoomVersionId) -> Option<Ordering> {
-        self.as_str().partial_cmp(other.as_str())
+        Some(self.cmp(other))
     }
 }