Update MSRV to 1.84.0

And appease clippy (`__CARGO_FIX_YOLO=1 cargo clippy --fix` plus some
manual type shuffling).

src/database/key_value/rooms/state_cache.rs

@@ -182,9 +182,9 @@ impl service::rooms::state_cache::Data for KeyValueDatabase {
         .ok();
 
         let in_room = bridge_user_id
-            .map_or(false, |id| self.is_joined(&id, room_id).unwrap_or(false))
+            .is_some_and(|id| self.is_joined(&id, room_id).unwrap_or(false))
             || self.room_members(room_id).any(|userid| {
-                userid.map_or(false, |userid| {
+                userid.is_ok_and(|userid| {
                     appservice.users.is_match(userid.as_str())
                 })
             });

src/database/key_value/sending.rs

@@ -86,12 +86,10 @@ impl service::sending::Data for KeyValueDatabase {
     ) -> Box<dyn Iterator<Item = Result<(SendingEventType, RequestKey)>> + 'a>
     {
         let prefix = destination.get_prefix();
-        return Box::new(self.servernameevent_data.scan_prefix(prefix).map(
-            |(k, v)| {
-                let k = RequestKey::new(k);
-                parse_servercurrentevent(&k, v).map(|(_, ev)| (ev, k))
-            },
-        ));
+        Box::new(self.servernameevent_data.scan_prefix(prefix).map(|(k, v)| {
+            let k = RequestKey::new(k);
+            parse_servercurrentevent(&k, v).map(|(_, ev)| (ev, k))
+        }))
     }
 
     fn mark_as_active(

src/database/key_value/users.rs

@@ -522,8 +522,8 @@ impl service::users::Data for KeyValueDatabase {
         &self,
         user_id: &UserId,
         master_key: &Raw<CrossSigningKey>,
-        self_signing_key: &Option<Raw<CrossSigningKey>>,
-        user_signing_key: &Option<Raw<CrossSigningKey>>,
+        self_signing_key: Option<&Raw<CrossSigningKey>>,
+        user_signing_key: Option<&Raw<CrossSigningKey>>,
         notify: bool,
     ) -> Result<()> {
         // TODO: Check signatures