Remove never-used client parameter from message handler functions (#13406)

Every single client-side RPC message handler function took an unused
`Arc<Client>` parameter. This removes that.

Release Notes:

- N/A

crates/call/src/call.rs

@@ -114,7 +114,6 @@ impl ActiveCall {
     async fn handle_incoming_call(
         this: Model<Self>,
         envelope: TypedEnvelope<proto::IncomingCall>,
-        _: Arc<Client>,
         mut cx: AsyncAppContext,
     ) -> Result<proto::Ack> {
         let user_store = this.update(&mut cx, |this, _| this.user_store.clone())?;
@@ -142,7 +141,6 @@ impl ActiveCall {
     async fn handle_call_canceled(
         this: Model<Self>,
         envelope: TypedEnvelope<proto::CallCanceled>,
-        _: Arc<Client>,
         mut cx: AsyncAppContext,
     ) -> Result<()> {
         this.update(&mut cx, |this, _| {

crates/call/src/room.rs

@@ -697,7 +697,6 @@ impl Room {
     async fn handle_room_updated(
         this: Model<Self>,
         envelope: TypedEnvelope<proto::RoomUpdated>,
-        _: Arc<Client>,
         mut cx: AsyncAppContext,
     ) -> Result<()> {
         let room = envelope